Censorship is stopping people seeing content everywhere. Facebook are only stopping people seeing the content on Facebook.

The idea that Facebook has a monopoly on video is weird. If someone wanted to grow an audience around their video content would you suggest they post the videos to Facebook to do it?

Network television censors profanity and nudity. Indeed the govt requires much of it. Everyone calls it censorship. Yet you can still see the unedited versions of the same content at a theater or on cable.

Maybe if your idea of censorship hinged on govt involvement it might fit a bit better. Though I'd still say we need to be able to talk about censorship by other organizations besides govt, and that the dictionary definition of the word covers this.