The problem with that is that the generated child porn would presumably derive from training data containing real children and child bodies, so it's not complet

The problem with that is that the generated child porn would presumably derive from training data containing real children and child bodies, so it's not completely "not real". This isn't the same thing as a drawing or 3D model made by a human. Or maybe it is, what if a pedophile looked at some clothed children, drew very realistic pictures of them naked, then used them as child porn? I think a lot of people would have a problem with that too.