I don't think they are invoking section 230 at all in their defence. It's a pure first amendment defence - their decision to remove something from their platfo

I don't think they are invoking section 230 at all in their defence. It's a pure first amendment defence - their decision to remove something from their platform is protected by 1A (no compelled speech). And their justification for removing it is just protected speech. Now if they were defending themselves for _not_ removing something that was actually defamatory they might invoke section 230. 230 merely strengthens free speech by giving the platform some immunity wrt what their users write. It doesn't require them to be neutral in any way.