"and also posted that anyone who posts untrue content should be banned (in the same post)"
Now you are the one lying, that poster did not say anyone who posts untrue comments should be banned, he said there should be consequences, very different, consequences can mean a range of sanctions such as a fact check flag or a temp suspension. There are numerous fact check flags on Trumps posts especially from 6th Jan where he was constantly lying
Here's another view. Surely society should expect that comments posted on any media should be truthful. And if not, especially when it's obvious the comment is not truthful, there should be consequences.