> "computer generated art" is also not protected under copyright

These AI's mix art that could be under copyright and very different licenses (I've seen watermarks while using them). You can assign any license you want to the output, but that doesn't mean the owner of the original art won't find a similarity and sue you. So basically it's a risk. Laws are blind, there is no automatic winner in a legal dispute, what you can prove in court and the laws that apply to your jurisdiction are what count, and also how much money you will spend in the legal process whether you are right or wrong.

Not a lawyer! (tm)