Temur Delver has been a deck in Modern for a while now. It even won a Grand Prix way back when. Since then, it's kind of faded into obscurity, but new cards tend to breathe new life in old archetypes. For a deck that relies on Tarmogoyf to do a lot of the heavy lifting, a 4/4 trampler for G is probably what the deck wanted.
Jordan didn't stop there though. While having an extra four power creature makes Stubborn Denial a reasonable include, he also went with a few stranger additions. Curiosity is the first one that strikes me as odd, as Curiosity seems like it's "win more" on a Tarmogoyf. Delver of Secrets is so fragile that I can't imagine a Curiosity staying on it for long, but I suppose that's what Disrupting Shoal is for.
Most decks don't want to play Disrupting Shoal because there's no telling what sort of spell you're going to need to counter, and there's no guarantee you'll have the perfect card to exile. Gitaxian Probe does help to some extent, but you won't always have it. There's also no way to re-gain the card advantage you lost, but maybe all you need is a turn or two to cement a massive advantage.
Some people aren't going to feel okay playing a deck with such a low land count, but Gitaxian Probe, Serum Visions, and Thought Scour definitely help out in that department. If you want to play a deck like this, you're going to have to get used to keeping some one-land hands.
If your maindeck aggro cards aren't getting the job done, a brand new deck waits in the sideboard. With Huntmaster of the Fells, you'll have a much better lategame. With Blood Moon, you'll likely end the game quickly and easily.