I personally have a hard time believing that a Russian main character captain will take center stage of any possible new ST TV series any time soon.
I don't see why. The Cold War ended a generation ago.
Sure, odds are that any lead character in an American show will be American, but I don't see why any show today would have a specific prejudice against Russians. Particularly a Star Trek
series. Russia was a pioneering power in space exploration and has been honored for that many times in Trek.