It’s worth wondering what would happen if somehow the child-like Hulk returned and took back control. It would be understandable for him to be angry, not just at Banner but at his fellow Avengers. No-one stopped Banner from using his “solution”, nor did any of them attempt to restore Hulk. Hulk made it clear in Thor: Ragnarok that he felt underappreciated, and basically being shut out by Banner for five years would certainly build on those feelings.
If the MCU Hulk did manage to regain control, he could go on a rampage that makes all of his past attacks pale in comparison. If so, it could take the full force of the Avengers to rein him in. For this to work, Marvel could make World War Hulk the main plot of Avengers 5, due in part to the fact that solo Hulk movies are still off the table. Marvel could also move Hulk in this direction if their intention is to properly retire the character. Or, their plan can be to deliver a major Hulk story that finally gives him the spotlight. A story like this would certainly appease the fans who were disappointed in Marvel’s decision to let Bruce Banner overshadow (and even replace) Hulk in the last two Avengers movies. In contrast to Avengers: Infinity War and Endgame, Banner could take a backseat to Hulk, who could become the dominant personality for the first time since his stay on Sakaar. All things considered, a World War Hulk movie may be the story that the MCU’s Hulk needs.
