The Marvel Cinematic Universe's Hulk is going through perhaps his biggest change to date.
What appears to be promotional art for the upcoming Avengers 4 surfaced earlier today showing the surviving heroes of Thanos’ Infinity Gauntlet-powered snap banding together, and the strongest Avenger is wearing not just black pants, but a black (or purple) top as well. Assuming the art in question is real -- it looks like it would be used for backpacks or a lunchbox, yet has no artist's signature -- it could mean a number of things for Hulk.
For most of Infinity War, Bruce Banner was unable to summon his other half when he needed it, including during the film's climactic battle of Wakanda. Whenever Bruce tried to transform, the change would actually stop midway, and it didn't seem like a solution with an easy fix. The choice of whether or not to be Hulk has never been up to Bruce fully, and the time without his other half has likely given him a new outlook on a side of himself he didn't think he wanted, and a solution to his transformation issue.
It’s possible that Hulk’s new outfit is laced with something capable of triggering a transformation when Bruce needs it. It wouldn’t be out of the realm of possibility; with Stark still alive, he and Banner could easily conceive of such a suit for Bruce to use, one that combines the former's tech with the latter's gamma-focused research.
There also appears to be blue lines along the edges of his forearms, which could mean that if our Stark suit theory is true, Shuri may have had a hand in making it as well. After all, it would make sense to incorporate some Wakandan Black Panther tech into the outfit. Plus, with Hulk's mental state being somewhat fragile at the moment, the added protection a vibranium-laced outfit would provide could help boost the Jade Giant's confidence levels a bit for the next time he finds himself face to face with Thanos.