Toxic on stream but not in game?

I wanted to know the opinion of Rito when it comes to toxicity. Like lets say a streamer is playing his or her best, not flaming anyone in chat, not int feeding, trolling or griefing, but on his or her stream that person is saying horrible things like, "This Lee keeps spamming bahahaha like some sort of super mario character that should be gunned down on the street like the degenerate he is." Is this bannable, where he's not saying anything in game and is actually not ruining other people's experiences, but on his or her own stream being a really toxic player who says really bad things and sets a bad example for the league community?