Well true it's not gonna happen "very" soon. You'll basically need source code for games that generalize this stuff, game engine code bases that can encompass various game styles. And presumably a lot of "data worker" work which translate existing games into design doc so it can be used for training.

But most AAA games share very similar gameplay elements just with different art and music and characters and story, one or two new features. Much of the code base is like "player / camera controller" and then a lot of items and weapons and levels and encounters.

So you don't need to manage an entire colossal code base. But if you imagine just a selection of very strict genres, like first person shooter or realtime strategy game, this provides a rather restricted code base where most is art generation and that is definitely possible. Even MMORPGs like WoW.

You might still need or want e.g. a concept artist that designs characters or supervises art styles. But it's going to be possible for hobbyists to do the work of multi million dollar studios. With a little side of slop of course lol. No doubt "handmade" games still are potentially better but due to budget constraints have not often been and in this future scenario just won't be commercially viable. It's going to be patreon funded game designer crews. And bye bye fucking corporate games industry.