I'm not sure how they'd enforce it while they still accept other digital art, But it seems a good decision, both on their stated concern about copyright (it's

I'm not sure how they'd enforce it while they still accept other digital art, But it seems a good decision, both on their stated concern about copyright (it's all a synthesis of the training sets, but who knows how much?), and also that AI art is effectively an infinite output stream that would very rapidly swamp all human output.