Does this mean people inside Russia can't access sites outside, or that outsiders can't access sites inside Russia? Or both?
I've personally have been seeing Russian endpoints disappearing one and one and DNS records slowly disappearing too, from the outside while watching Russian infrastructure since day one of the invasion. Seems they are so overpowered by all the attacks happening on their infrastructure, that they opt for just shutting of most connections at this point.
However, as long as you have a route into Russia (Tor with Russian exit node, VPN on dedicated server in Russia or "Acquired" residential/company computers) that you can use, this change won't do much to stop the attacks. Although it'll get rid of the constant ddos many beginner "hackers" are currently performing against them.
Seems a little suspicious for a 2 day old account. Almost like… propaganda
To put in another perspective, nothing in Russian IT infrastructure has to change in order to control who sees what on the "Russian" internet. So if it was all about "controlling people's mind", then this would be overkill.
But if you're getting hit by constant attacks from outside the country, this move makes a lot of sense in order to stop the attack, although also overkill but if you're not very skilled, it would probably stop many attacks.
The only reason i am asking here is because the time is ticking, and once the block goes into the effect, I wont even be able to relay to him any useful info on how to go around it. So is it pretty much either pre-emptively taking care of it or being stuck hoping that he will figure something out on his own?
Tor will most likely continue to work, as long as there is a route to an entry node, your father would be able to navigate the web. However, they can try to stop Tor, and I'd advise you to read through the Troubleshooting steps from Tor preemptively: https://tb-manual.torproject.org/
Also try to lookup ways to still use Tor even if the usage is blocked. There are a couple of ways that could help him in that situation.
If you do end up losing contact with him (because of internet blockage), I can try to do my best to get you two in contact again, one way or another. My email is in my profile if you want to reach out.