Total reserves (Naval, AF, and Army) are around 2-million for Russia. The number that gets discussed is 300,000 for this activation. My humble guess...most all of the 300,000 are Army reservists, who fall into the infantry, logistics and tanker occupations.
The airline ticket business reflects routes to countries that have friendly visa-situations with Russia.
It is conceivable that when they start calling for activation orders...that 5,000 to 10,000 of this group have already left the country. I doubt if anyone is really tracking those who left Russia.
You are confusing regular reserve and BARS active. The former is like 25-30+ million. BARS are already in Ukraine, the plans are to draw from ROTC grads and the regular reserve. I don’t see a problem. The idea that everybody in running away is simply ridiculous. I doubt if any of them is going to see action until spring. And then they are likely to stay home to warm chairs for regulars who’d get deployed.