The NBA is an organization who's job it is to set rules that teams, athletes, and referees can participate in. They can choose to fire refs who behave this way, and they would because they make more money if the refs aren't racists (especially now that they're getting more into racial activism)

Twitch is basically the NBA of their streaming platform, as in they set rules for how streamers, viewers, and moderators interact. Twitch can create whatever arbitrary rules it wants to maximize their revenue. If advertisers stopped caring about controversy, or if Twitch suddenly found a better revenue source, they would surely pursue it.