It doesn't need csam data for training, it just needs to know what a boob looks like, and what a child looks like. I run some sdxl-based models at home and I've observed it can be difficult to avoid more often than you'd think. There are keywords in porn that blend the lines across datasets ("teen", "petite", "young", "small" etc). The word "girl" in particular I've found that if you add that to basically any porn prompt gives you a small chance of inadvertently creating the undesirable. You have to be really careful and use words like "woman", "adult", etc instead to convince your image model not to make things that look like children. If you've ever wondered why internet-based porn generators are on super heavy guardrails, this is why.

The whole point of diffusion models is that you can generate new concepts using training data. Models trained on any nsfw images can combine those concepts with any of its non-nsfw concepts. Of course, that's not to say there isn't CSAM in any training data, because there objectively has been in the past, but there doesn't need to be any to generate it.

Ai is able to fill in the last field in a table like "Old / young" vs "Clothed / naked" when given three of the four fields.

Please reiterate your statement but instead using the "goose chase meme" format.