Russia is 14% Muslim. Given their current birth rate Muslims will be 1/3 of the population in 12 years.
Russia has the highest abortion rate in the world, 53 abortions per 1000 women per year. I doubt that many of these are Muslims. I doubt the Chechnian tyrant wants to kill his troops in Ukraine. He would probably rather keep them safe for action against Putin or his successor. Of course he could send troops he doubts to Ukraine to get them out of his hair.