Importantly, we're posting on a forum where this exact idea is true. HN doesn't stop all hate speech, or flaming and what have...but the moderation system stops enough that people generally don't bother.
I think spaces that effectively moderate AI art content will be successful (or not) based on these same factors.
It won't depend on some brittle technology for predicting if something is harmful or NSFW. (Which, incidentally, people will use to optimize/find NSFW content specifically, as they already do with Stable Diffusion).