When an AI is able to take and write every single line of code, generate all the art, and debug it just by having someone as code dumb as a CEO type in a prompt, I'll believe his words and eat my shirt.
There is a possibility something like this will be possible in the future, but it's not going to be an achievement of AI, it's largely going to be the achievement of regular developers creating a general-purpose game engine that can be used to put together a game block by block, which can be utilized by both human game designers and AI. (Likely to better effect by the former.) I can imagine Entity Component Systems will play a big part of that.
One of the biggest blockers for AI making games is going to be testing it to select for better performance. With text it's relatively easy to see if some text an AI produced is plausible. Images are also plentiful, but that's a lot more subjective. With both of these it would also not take a massive amount of time to add a human element. It's quick to check if a paragraph or image looks like it is a good response to the input promt. A game, however? How long do you need to play it to see if it's fun? At best, perhaps, you can write an AI to control a bot character to see if it's technically playable.
I don't want to even think about the electricity that wlll be wasted training such models.
25 years might actually be a potentially realistic timeframe for that. But I'd still bet on a little longer myself. I hope it happens within my lifetime.