I disagree. The core of gameplay is handled in the code. Art by itself doesn't make a game fun. Think about card games like Poker, Black Jack, Spades, you name it. Nobody plays those games because the cards are a particular art style, they play them because the rules and strategy are fun.
You can have AI create the rules for you, or you can have the AI create the code that implements the rules. It's not different for art. You can have the AI create concepts for your, or you can direct the AI towards a specific vision.
I argue that while it is possible to direct AI to implement your artistic gameplay idea faithfully, it is not possible to direct AI towards an artistic vision without losing a lot in the handling of the details.
There’s no right vs wrong, for art the details Are the fun part.
I’m enough of a sucker to think that there’s art in code as well (not just the game design but implementation too) but clearly less and it’s not nearly as visible.