Apparently Twitch's employees like these policies for ethical reasons, and/or their businesspeople and advertisers think these policies will bring in more money. Personally, I like these policies and I'd like to see more of this kind of proactive action. I like Twitch more knowing that they have this policy. It shows that they understand their role in shaping public discourse and are taking responsibility for it. It's a difficult balancing act, and there's plenty of ways it could be done badly, but pretending that platforms and their algorithms don't play a role in public discourse is silly.
I do feel most of this whole issue could be sidestepped with some long overdue antitrust enforcement.