The danger, and likely future however is sites like DraftKings and Fanduel setting up slots and being allowed fully, then sponsoring streamers. Basically, the danger with banning the unregulated stuff yet still being very supportive of gambling (which Twitch and more so Amazon obviously are) is opening a door to further normalization and mainstream acceptance of gambling (see Poker taking a nosedive due to regulation yet paving the way for the massive boom in fantasy sports)... but hey, at least some guy in Curacao won't be getting the millions, some CEO and shareholders in the US will. Still, it is a good step by twitch, and I hope it really does end the #ad gambling streams.
We may see a surge in Fantasy sports betting and e-sports betting though. Having xQC watch NFL games on stream while betting thousands on regulated sites is probably a future Amazon would be very happy with.