I mean, while you're technically right, this is the president's stream. It's well within a stream's rights to censor unrelated content. I do it on other streams I moderate all the time, because most streams have a specific topic.
And it's not that I don't mind a few unrelated posts, but what firestar is doing is very, VERY excessive. I've asked him to stop, and he's refused, so I think actual action should be taken.