I don't believe that this is coming. It would have large economic costs (how to conduct international business with "friendly" countries? etc. etc.), would piss off a significant share of the population (e.g. online gamers) etc. It's just not worth it.
For countries like Russia, the goal isn't necessarily to cut off all connections, the goal is to discourage it, make it expensive, annoying, slow, so that a large majority of the population will opt to use the Russian internet.
I don't know. People said the same thing about the invasion to begin with. That it would cause significant economic harm to Russia, cause civil unrest, and so on. Yet they did it and pulled through somehow.
I don't they'll hesitate to do it if they see the need to. Putin wants the Soviet times back at any cost. He has many strings he can pull if he feels threatened.
According to a Russian resident I follow on social media, over the last 2 years Russians improved their localized circuses: VK, mail.ru, etc. The guy says these are now somewhat close to the originals i.e. Facebook, Instagram, YouTube.
How is the Russian equivalent of Marvel doing? Is there a strong Manga production? How many AAA games does Russia produce? K-pop is pretty popular in Russia, how about that?
Internet/media has a very long tail, which Russia can't hope to replace.
For countries like Russia, the goal isn't necessarily to cut off all connections, the goal is to discourage it, make it expensive, annoying, slow, so that a large majority of the population will opt to use the Russian internet.