Kazakhstan is a bi-ethnic state. That would only apply to the Northern parts of the country inhabited by Russians (and Almaty). Kazakhs are no Russians alright, and there's a growing de-russification trend there. There used to be almost no ethnic Kazakh hockey players at all. Now if you look at the list of names of their U18 junior national team, you get kids like Sayan Daniyar, Daniyar Gabdullin, Bari Saburov, Adilbek Dzhangazinov, etc. Hockey is growing in Kazakhstan and their programme is improving. Kazakhs have never been so prosperous as they are now and they've never had a state of their own before. They're investing major resources into the sport, too. So the comparison is not valid.
Belarus, on the other hand, is going extinct as a cultural entity with most young people not being able to speak Belarusian at all.