I doubt it, Team17 doesn't sell their games in Russia, so they probably won't bother making Russian localization, it will allow them to save some budget, it's like additional $100K per extra language.

And I know that there's publishers like Activision-Blizzard that too doesn't sell their games in Russia, and yet they still make fully voiced Russian localizations (Diablo IV for example), but not many publishers can flex like that! But you need to understand that this game is not Diablo, it's a very niche game, and there's not so many russian-speaking gamers that will bother paying full price for a game with anthro characters...

I mean, personally, yeah I'm gonna purchase Rockbeasts day one, no matter what language support it will have (unless it will have a very unreasonable price), but even if it'll have Russian language, I would still prefer to play it on English, because English localizations usually has better fonts and less bugs (See Bloodlines 2 for example, non-English languages doesn't have all dialogue lines...), but I know for a fact that not many russian-speaking gamers are gonna purchase this game, and having a Russian localization doesn't really make a big difference in a global scale. =/