The good old brain drain over-hyped phenomenon.
It is completely impossible that "intellectuals" all switch off like that, at best a few important ones who dislike the current government, and then if its just book sellers and philosophs its not going to hurt at all.
I would be more worried of scientists and military officiers selling their knowledge to other nations, but this is always way more "locked" for obvious reasons.
How money is linked to brain drain though? Money is more cynical and does not follow politics, the people who least welcomed economical sanctions are the capitalists...
The unrest in Ukraine boosted Russia population up to 1 million thanks to refugees, if they manage to assimilate them and give them jobs I think thats their win. While Ukraine is depopulated and many of its south east industrial zones are completely destroyed.
I would go as far as saying that its in Russia interest to not annex those barren no man's lands.