Hentai depicting animated/drawn fake children means that 0 children were harmed, thus CSAM rules do not apply.
My guess is that slop generated CSAM images are NOT 'child sex assault' in any way. Are they icky? Uh, hell yeah. But it seems similar to hentai here. There's nobody being sexually assaulted. Hell, there is nobody at all - just a large multi-billion array of floats.