This is an important distinction. Claiming someone else's statements are false in fact is not censorship. What it is though is confirmation that Facebook is a publisher which publishes editorial opinions about things. (It's incidental that they claim their opinions are facts, publishers have been doing that since the beginning of time.)

The only real question is why the government exempts this particular corporation from following the usual rules that publishers have to follow.

It is more of a soft censorship.