I can understand the perspective that if someone is making claims that your platform / forum allows “free speech” then people are justified in being upset when this is not the case.
On the other hand the rule since the days of dial up BBSs is: the sysop can do whatever they want with their system, and you are owed nothing. If people do not like how they operate, then they migrate somewhere else. Sure it sucks when you get on the wrong side of a sysop and get banned from a popular board, but that’s just the game.
The era of mobile phones / internet is truly the eternal September. :)