I may be totally wrong on this, but if Vinch — a russian man of fighting age — has managed to get himself outside the country right now, I imagine he might have limited desire to go back to Russia the way the things currently are.
But ofc I don’t have any real insight into his situation.
And I agree (in my ignorance) with what others have said — AOE2 is not such a large e-sport to warrant intense scrutiny, the players aren’t really representing their home nations, and Russia at this point is used to foreign competitions forcing their players to play under a different flag.
So not only would the Russian authorities probably not care / notice in the first place, but he would have plausible deniability that the tournament organizers forced him to do that if he wanted to participate, and it wasn’t his choice.