Up until very recently, Twitch's moderation tools have been total garbage. I can only assume that they put the chat moderation stuff into their partner contract so they can get rid of undesirable partners easily. "We hate you, and here is a message that your moderators missed so buh bye." I also think that partners are well aware of the possibility of Twitch getting rid of them at any time with no recourse; this is why they heavily advertise their social media, Discord, and YouTube channels. You don't ever want to put all your eggs in one basket. If they have to move, it is likely that some of their audience will follow them.

Overall, I don't think Twitch is using chat moderation as much of a bargaining chip in practice. There are cases of streamers rallying their viewers to abuse other streamers. But in chat, really all you can do is have your bots spam racist messages, ASCII art, or "CUTE BOTS AYAYA CUTE BOTS". Links are mostly banned in practice (not by Twitch but with common extensions), Twitch moderates emotes (aggressively now, even for partners), and whatever hurtful things people say... most people opt out of by watching someone else. All of the stuff that is going to result in legal action tends to happen outside of Twitch (Twitter and Discord are cesspools of drama; read something like /r/OverwatchTMZ for examples).

I guess my point is, I don't think Twitch chat is going to be affected much by any regulations. I suppose if your chat consistently harrasses minors, you could be banned. But it seems very very uncommon even in the extremely toxic gaming community. When it does happen, it's incited by the streamer, and so the specifics of chat don't matter.