I haven't read much about it, but I have the feeling that all gambling sites just continue to accept Russian gamblers and that this has not been banned at all. There is also no legislation for it. Those gambling sites are located in countries where there is little control. And if you were to introduce a ban, Russians would also be able to gamble at other sites. It generates too much income to put a ban on it I think. That's not so easy.
In as much other Russian government never ban any gambling site because of what is happening now, then I see no reason why a gambling platform would ban Russians gamblers from using their platform. Every gambling platform is looking for money to make more profits from users. So it is hard for such can of thing to happen. Jumping out of a gambling platform because of boycotting the use of gambling platform owns by Russians looks bad and weak.