Remember the World Championship?
There were three decks: Ramunap Red, Temur Energy, and U/B Control. From what I've seen on social media, everyone seems to have noticed that U/B Control was the one of those decks untouched by bannings, so level one is the assumption that U/B Control is the new best deck/deck to beat.
Rampaging Ferocidon wasn't a great card against U/B, but Ramunap Ruins certainly was, and the matchup between Ramunap Red and U/B had been close enough that I think between that ban and the printing of Moment of Craving (yes, that's my pick for the card that matters here, not Ravenous Chupacabra), U/B should be solidly ahead in the matchup. I also think Temur Energy needed absolutely everything it had going for it to be competitive with U/B Control, so I think the bans are clearly sufficient to leave U/B Control on top of that three deck metagame.
But what about the larger Standard metagame?
There, I think U/B Control actually has some weaknesses.
U/B is fantastic at killing creatures and planeswalkers, but quite bad at answering artifacts and enchantments. If you want to beat them, artifacts and enchantments are a great way to do it. Fortunately, this format has a ton of really powerful artifacts and enchantments against U/B. Let's look at some options:
Hidden Stockpile has always been a nightmare for U/B, because it's cheap enough to sneak under counterspells and provides a threat they can't easily answer. Moreover, if build your deck to be essentially creatureless and play answers that exile creatures, The Scarab God is mostly just a vanilla 5/5, which isn't exactly an impressive finisher for a control deck. I found the Abzan Procession deck to be a very difficult matchup for U/B Control before the World Championship, and I don't see anything that would clearly change that.
Treasure Map is a flexible enough card that almost anyone can use it to improve their matchup against U/B Control. Remember Ben's Stark's Treasure Red deck? If that doesn't show that anyone can play Treasure Map, I don't know what would.
Silent Gravestone is a narrow sideboard card, but it's worth noting that it cripples both Torrential Gearhulk and The Scarab God. Often, U/B is winning by enough that they just need a random threat to finish the game because they've taken over with Search for Azcanta, but that's not always the case; so if your deck has problems with their finishers specifically, rather than the general engine of the deck, this is a narrow but very effective sideboard card--this is probably most relevant for God-Pharaoh's Gift decks, which can often keep up with the grind and whose artifacts U/B can have a lot of trouble with, especially if they can sneak a Gate to the Afterlife onto the battlefield but which can get completely trumped by The Scarab God. If The Scarab God can't exile your creatures, U/B will have no hope of beating God-Pharaoh's Gift, and even Champion of Wits will be difficult to keep up with.
On the subject of invalidating their threats, how exactly is that deck ever beating a resolved Profane Procession? I'll help: It's just not happening in their previous configuration. The answer is that U/B will had to adapt by playing something like Commit to be able to get it off the battlefield before playing a creature to win the game. It's not that hard for U/B to play a couple copies of Commit and find them with Search for Azcanta before trying to kill you, and until they want to cast one of their threats, Profane Procession doesn't do anything, so it might ultimately turn out to be a bad card against them if they have a few answers, again, depending on whether your deck does something that forces them to be able to use their finishers, and, to some extent, on how many finishers they play/draw--If they only draw one, it's not that big of a deal; but if they draw two, the double mulligan might catch up with them before they find their answer.
The other issue is overloading the few answers to artifacts and enchantments they can manage to play. It's reasonable for an Abzan control deck to have Treasure Map, Arguel's Blood Fast, Hidden Stockpile, and Profane Procession, on top of other things that can incidentally be large problems, like Ixalan's Binding.
So, what's the point? Well, to start with, I don't think U/B will be the uncontested best deck in Standard, because blue and black as colors simply don't have enough good answers to the wealth of powerful grindy enchantments in Ixalan and Standard, in general.
So, will Abzan Control be the deck to beat? After all, Ixalan is a tribal set, and Abzan Control is a Fumigate deck that can also play Settle the Wreckage and whatever other answers it wants.
I don't think so. From my testing of Abzan Control, it wasn't just a terrible post-sideboard matchup against Temur Energy that got in the way for that deck, the biggest problem was Approach of the Second Sun. The finishers in U/B are atrocious against Abzan, so they try to grind for a while and eventually lose to tokens that they don't have a good way to clean up, but the white version has Cast Out, which is a much better answer to opposing enchantments and artifacts than black can muster, and Approach of the Second Sun itself, a trump finisher in a long, slow matchup, rather than completely ineffectual finishers. While the core of the deck is similar, Approach replaces all the worst cards in U/B with the best cards in Approach--in other words, where both decks have counterspells, the U/B deck is hoping to draw them while the U/W deck would prefer to draw its white cards but can settle for drawing counterspells. The result is that the overall win percentage difference is night and day.
It's possible that this will lead to the normalization of Esper Control, as U/W Approach will likely find that it has problems with U/B Control because it's extremely hard for a control deck without Duress to beat a control deck with Duress. Basically, if U/B is the better deck but Abzan Control or something similar becomes a substantial enough metagame presence to demand respect, then U/B might have to add white to give itself a fighting chance against that kind of deck.
Another concern for U/B is that it has also had a truly horrendous matchup against black aggro (with or without Hazoret). Black creatures hit harder than red creatures, but they're easier to block and they're harder to kill (Dread Wanderer and Scrapheap Scrounger). Being easier to block doesn't really help U/B, and harder to kill threats that hit harder and can easily be supported by Duress results in a combination that's extremely hard to beat. Without Ramunap Ruins as a draw to make aggro players play red, we might see more black aggressive decks and B/R aggressive decks--decks that previously couldn't exist largely because Whirler Virtuoso was basically unbeatable--pick up some metagame share, which should make things hard for any blue control deck (Abzan Tokens can likely reasonably defend itself here).
Oketra's Monument should play well against this style of aggressive deck, as should most God-Pharaoh's Gift decks, since both are very good at incidentally blocking 2/1 creatures at very low cost. I'm genuinely not sure how either of these decks will fit into the larger metagame.
Let's talk about some individual cards and some new decks.
Ravenous Chupacabra has gotten a lot of press (largely due to Patrick Sullivan's excellent rant --unfortunately, Patrick is so well-spoken that I think this delightful rant will cause a lot of people to really overestimate the significance of this card for a while), but I think there are actually not that many decks that will want to play a lot of these. I think it's a worse fit than Vraska'a Contempt if your deck is using Search for Azcanta and/or trying to operate at instant speed, and I think the likely prevalence of control decks will make it a weak maindeck card. If it has a home, I think it will likely be in decks with Liliana, Death's Majesty or God-Pharaoh's Gift. People talk more about its synergy with The Scarab God, but I don't really think an active The Scarab God needs the help.
Adanto Vanguard is an impressively powerful threat that was held back by not being great against Temur Energy. It will be a staple of white aggressive decks, which may succeed largely on the strength of this card. As a result, both Moment of Craving and Golden Demise are both very important cards, since Adanto Vanguard can't save itself from -2/-2.
In my last article, I concluded with a deck that I thought wouldn't be able to compete with the Standard metagame, but it might do well in an alternate universe dominated by control decks. Well, looks like there might be a reason to try that deck out.
Merfolk is in an interesting place. It has enough playable creatures, but the question is whether the supporting spells offered in blue and green are sufficient. Honestly, after looking at it a bit, I'm most optimistic about Merfolk in a world where they can afford to play four Spell Pierce main deck--It's a tempo deck with a lot of card advantage that most needs to avoid getting destroyed by a sweeper, and if we can play four Spell Pierce and sideboard four Negate, this becomes another interesting take on an aggro control deck that might be able to prey on Search for Azcanta decks and Fumigate decks.
And what about Rekindling Phoenix, currently the second-most expensive card in Rivals of Ixalan? Will this lead to the creation of a midrange red deck that has a curve too high to play Hazoret the Fervent, and instead plays removal into large creatures like Rekindling Phoenix, Glorybringer, and maybe Burning Sun's Avatar? This big red deck could use Treasure Map and Chandra, Torch of Defiance to try hang with control decks while playing good cheap removal for other aggressive decks and a great set of fliers to win the game. Abrade is looking like a nice card to have moving forward, where the tier two decks that were built around artifacts (or Winding Constrictor) now have a chance to move to the forefront and pick up substantial metagame share. In fact, between Vehicles, Winding Constrictor, Oketra's Monument, Treasure Map, and God-Pharaoh's Gift, Abrade is a card I think people should very highly value being able to cast when considering their deck choice for early events in this Standard format. Sweltering Suns is another great card to have access to early on, while people might be exploring tribal decks more than they likely will later in the format.
So, given all these decks with real strengths and weaknesses, what would I advocate moving forward? I think U/B is too obvious and too beatable by people who are trying, regardless of how busted Search for Azcanta and The Scarab God are. I think U/W Approach is likely a better way to play a control deck for the moment (consider adding Baffling End to prepare for Adanto Vanguard and Scrapheap Scrounger), and it will be a strong choice for the first weeks.
To beat that, I'd want to be a blue aggressive deck or a deck with a lot of relevant planeswalkers like Chandra, Torch of Defiance or Nissa, Steward of Elements. Failing that, I suppose I'd want Duress and Arguel's Blood Fast, and possibly even Lost Legacy in my sideboard.
Esper Gift feels like a deck that does something powerful that people might sleep on at first and that can be built with a lot of tools to combat control decks. If you want to put the work into finding a good version of that, it could be good. I'd start by trying to play Glint-Sleeve Siphoner.
I think that if I were preparing for a Standard event, I'd try decks out in the following order:
Adanto Vanguard Aggro
After talking through the implications for the future, I'm pretty optimistic about Standard following these bans. It's always possible something will turn out to be too good, but at least for now, there are a lot of decks that look like they could be viable. For the last few weeks, I've been excited that I might not have to play this Standard format at all if I skip a GP or two, but now, I almost wish this coming PT was Standard so I could really dive into these things. I say almost because Modern is also great, and I'm happy to get to play it at the PT and to be able to put a lot of time into drafting, because, aside from the fact that there are a ton of really obnoxious rares in Rivals of Ixalan, I'm enjoying the format out of the gate a lot more than Ixalan.