If they can remove her ads, they can remove anyone’s ads

This was always the case. This concept that "just now" companies like Twitch have been demonetizing and banning people for whatever reason they see fit is something that's been going on for years. You're probably just too young to realize it or weren't paying attention to the consequences of stuff like this because it didn't affect anyone you cared about. Which says alot about you as a person if this happening to a hot tub streamer is your first wake up call to this long standing situation.

I guess every small streamer deserves to get fucked too?

Channel size doesn't matter. If you bite the hand that feeds you, expect to starve.

If you're a streamer, no matter how big of an audience you have, if your main source of income is advertiser revenue then you should probably start paying attention to what advertisers do and do not like. This is the performers responsibility to figure out, not Twitch's or The advertisers themselves. They can afford to ditch someone like Amouranth if they feel she's doing more harm to their brands.

Hint: Advertisers want to reach into as many markets and demographics as humanly possible. That includes kids. Which means you have to have curated, family friendly content. Do you honestly think they want their ad's running on Hot Tub streamers channels when they want to present a family friendly brand? Hell no.

Pull your heads outta your ass and join the rest of us in the real world.