This is absolutely true. Look at text prediction models as an example (e.g. GPT-3). One of the biggest (if not the biggest) applications was story-generation tools like AI Dungeon. Guess what most people actually used AI Dungeon for? Erotica. Guess what happened when OpenAI cracked down on it? A huge portion of the userbase jumped ship and built a replacement (NovelAI) using open-source EleutherAI models that explicitly did support erotica, which ended up being even better than the original ever was. I can tell you that there is very strong interest in nsfw image generation in those communities, as well as multiple hobby projects/experiments attempting to train models on NSFW content (e.g. content-tagged boorus), or bootstrap/finetune existing models to get this sort of thing to work.