Moderation is a special case/form of censorship. In many cases, it's a desired or willful filter as the article suggests, but it is censorship of information.
Censorship doesn't have to be forced, it can be agreed to but it's still censorship. Rebranding things to look fuzzy and give positive perception doesn't change the underlying principle.
Manipulation of information be it omission, selection picking, burying in piles of noise, etc are all manipulative tactics most of which are used to follow the spirit/intent of censorship. It happens in restricted environments like China but also happens in less restrictive environments like the US, the method of approach simply changes around what's legal and possible. One could argue censorship approaches in free speech environments are the most resilient because they rely less on the difficult tight controls of information flow nation states like China leverage.