How about "AI ghostwritten"? That's a much closer parallel, and some commercially successful musicians similarly are "ghost produced".
I think the difference here is that the AI isn't a "work for hire" setup, it's more like a tool. It would be closer to buying algo sample packs, using Apple's Logic Pro AI drummer for part of the work, or other drum machines for example, and working your way around to glue them together into a composition.
The parallel would need to be between "tool" <—> "composition", rather than "author" <—> "composition" imo.