Yes you're right. There are lots of gamers on those platforms and gamers are really quick when it comes to adopting stuff like this. Though I'm thinking about how many of them will be ready to hold Bitcoin because it is volatile, those that would like to make use of cryptocurrency will mainly be using it for a purchase on the gaming site, so they might be jumping on stable coins till they get interest in holding a coin that is unstable.
 
Another thing is that these gaming platforms might even decide to create their own coins, because this has become the norm for most organizations these days, they all now prefers to have their own coin instead of accepting Bitcoin on their platforms. Let's wait till they are ready and they will announce what their plans are all about.