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.