AI-produced art is still human-made, as a person does the job of engineering a prompt and selecting from the generated images. The copyrightability of such work is unlikely to ever seriously be in question.
None of this leads to an obviously clear cut legal position wrt copyright.
If we were all honest, we'd give up the idea of copyright altogether where ML is concerned. You can't get much closer to "It's just math, man" than what it is currently.
Of course, "it's just math, man" isn't precisely a legal argument, either.