Yes, you're right with that statement, I don't know if you remember a thread made by a well-known member in the forum who was in a new casino, who didn't have a thread Ann here in the forum, but he played and was going to make a withdrawal and they started telling him no for very dumb reasons, and then that user said that he was a Legendary member of Bitcointalk and that he was going to make a thread on gambling just to advise everyone not to go into his site and mark it as untrustworthy, after This, they allowed him to withdraw, it really shows that the forum has a lot of power over the casinos, sports betting, it is because of the high level there is.
I guess, me too remember that case don't know exactly what casino but it really happened so if a casino is legit and don't even have representative here on bitcointalk still they care about the discussion going on here because they know it will affect their business a lot if they were marked as shady website also many reputed reviewing site also give attention to the experience of bitcointalk users about casino.
Maybe the guy threatened the casino and let them know that he is making a scam accuse thread on this forum, resulting for the casino to pay because they are also scared on what can happen to them. They know that bitcointalk is a big forum and not only limited to crypto discussions but also to gambling sites as well. Those types of casinos are not totally a scam yet but maybe they are confuse and they can end up on that path if some people will just keep quiet and do nothing after experiencing some problems.
The last thing that you said is true. Gamblingbro for example made some micro task for the users on this forum. User can leave their feedback on the casinos seen on his review site in exchange for some cash. This is to make their review site more transparent and not biased.