I don't know if there's an alternative platform to livestream yet but I think they will find sooner or later which they can stream gambling related streams.
Dlive is the other platform that I've known where they can stream. YouTube has streaming as well. But for Dlive, it's not that much users yet and viewers are still few.
So, it's like that Twitch is still the king of streaming against other streaming platforms. Facebook is also a good platform where has a lot of viewers for streamers but I don't know if they'll allow gambling contents to be viewed in their stream.