Sure, these don't have anywhere near the same reach when it comes to live streaming but people have been banned from twitch before and maintained an audience on other sites like these. There's also no "right to livestream".
We'll see how liberally twitch applies this new policy. All sites are literally allowed to do these things already, the only difference is they made it explicit. You can have a "common carrier" argument about regulation of private companies, but there's nothing in this announcement itself that makes twitch any different from others.
If they did that all the popular streamers would end up there pretty fast for microagressions. Lets not pretend this isnt political. I dont think billionaires should decide what is socially acceptable and what isnt.