Of course this is a very convenient coincidence here that a random emergency happens with a wanted man in board...
A similar situation from a few weeks ago.
they will send a strongly worded letter, no doubt about it
Flights already do a big detour around Ukraine because of their conflict with Russia. In fact, middle eastern hubs would love Belarus airspace to be restricted, it makes their routes much more competitive. Flights to SE Asia often fly further south, over the caucuses, Afg/Iran to SNG, or Iraq/Iran to Qatar since the GCC blockade. (Iran charges considerable fees for this btw, a good source of hard currency.)
I'm afraid Russia has everything to do with this incident. There is no way they would do this without Putin's okay. That he is willing to risk Russian airspace rights shows how desperately worried he is about popular uprisings.
The ops.group newsletter [0] is a great resource for understanding flight restrictions.
[0] https://ops.group/blog/assessing-the-risk-operations-over-co...
https://en.wikipedia.org/wiki/Iran_Air_Flight_655
Not that the US was wrong to be on high alert: