It certainly stretches the bounds of reason for me that you could put a person in an isolation chamber with a powerful computer with no network connection, and after they type a few words into it, if the output of the computer has certain qualities, they are now a felon and the output is illegal to possess.
But this seems like the world the “AI-regulators” seem to want.
A skilled artist can already easily do that and there's no law against it that I know of. (Granted, I haven't researched it because I'm neither an artist nor a pervert...)
Now, if they were drawn to resemble specific people and the producer of the "artwork" used them to harass those people, that's harassment. If they used them to groom other kids, that's an existing crime too. But my point was that the production of gross art in isolation, or the possession of it, didn't need to be criminalized. (Actual photographs of the same were criminalized because of the pretty decent assumption that minors were coerced, harmed, exploited. Probably all of the above.)
But this seems like the world the “AI-regulators” seem to want.