@davidrevoy @Tanath My 0.02€: I don't see a fundamental difference between a human artist's brain receiving inputs from what the person can see while looking at other artist's *published* creations, and an AI being fed the same creations although the AI will need a lot more inputs to learn than the human can do (AIs are still very inefficient at learning).
The morality issue starts when the user asks the AI “make a picture like David Revoy's”.
Maybe an “AI-not-welcome” licence may help?