Yeah, I also foresee it being like an Olympics style thing. Because we're seeing a surge in people from non-Russia CIS countries. Maybe it's only a matter of time before people get second passports.
Don't just throw out russian sounding names. Andrei Arlovski is Belarusian/American. Blagoy Ivanov is Bulgarian. Those guys just straight up aren't Russian I don't know why you mentioned their names. They probably will be released but that has nothing to do with a "russian quota." Abdurakhimov has a fight scheduled for September and prior to that won 3 for his last 4. Shamil Gamzatov is 1-0 in the UFC and has a fight scheduled for October. Sergey Khandozhko is 1-1 and also has a fight scheduled. Muslim Salikhov is on a 5 fight win streak he just got added to the rankings. Ramazan Emeev is 5-1 in the UFC, won his last 2, he's also on the border of the rankings. None of those either make any sense or are even relevant.
Of the others you mentioned, Kopylov has had visa issues, but is one of the younger guys and will certainly get a second fight unless he perpetually can't get a visa (which wouldn't be resolved within the contender series duration), Mustafaev and especially Tukhogov have winning records in the promotion. You're too scarred by the UFC releasing Akhmedov. The UFC doesn't actually just release good fighters on good contracts with winning records left and right. If they feel tied down by a veteran underperforming on a bigger contract then they may release him. Trying to extrapolate that to newer fighters on cheap contracts or fighters on big win streaks is not the move. Maybe if, say Salikohv or Emeev lost 2 fights in a row, perhaps. But neither of them have a fight scheduled, between the time to schedule a fight, lose, schedule another fight, lose again, that's way past the timeframe of the contender series that we're discussing here.