I feel like you're making valid points for interesting use of the technology. The problem is that only accounts for such a small percentage of AI output, that it is impossible to moderate for. It takes someone very skilled with the tech to be able to achieve what you are describing. I also don't think anyone is going to nitpick over someone performing a song written by AI as the artists performance is the human element we identify with.
Ban AI here and there can be another community for that kind of content.