Moderation is only relevant in a setting where rules of moderation are imposed.

For example, no one in the publishing industry is forced to publish a book that doesn’t conform with their rules. That’s moderation. However if the government attempted to *block* the publication of a book that would be censorship.

FFnet removing all works with explicit sex in them is moderation, because those works do not conform to the archive’s rules.

Attempting to stop someone from publishing a work on a platform whose rules it conforms to (for instance, trying to stop people from publishing incest smut on AO3) is censorship.