I wouldn't agree. Of course there's a push for homogenisation because everyone has to speak Russian, which is the official language of the state, but nobody is stopping people in the "national republics" from using their corresponding languages. Chechens speak Chechen at home, Tatars speak their language (if they want to). Modern Russia inherited this from the USSR's policies towards ethnic minorities. National languages are taught in schools.

I'm not a fan of Putin's policies here, but inside Russia it's certainly not oppressive in the linguistic sense. If you agree on the unity of the state (don't want actual political independence), you're free to use your language.