Protests never work under a dictatorship. See the Belarus experience and how much people was protesting. I believe that fleeing of IT guys will hurt Russian's economic more than being tortured in the jail.
Any possibilities of protest in Russia are suppressed. Putin has been doing this for decades. We don't have that much support. Visa/MS blocking affects ~1% of the population who want to flee.
Problem is that for just saying something like "no to war" at the street you can be inprisoned for years in Russia. Goverment have so much brute forces like police and OMON so they can handle anything.
Any possibilities of protest in Russia are suppressed. Putin has been doing this for decades. We don't have that much support. Visa/MS blocking affects ~1% of the population who want to flee.