However, he is right regarding few things (and i added a few things myself);
a. Russian population is shrinking in size - the slow growth rate that was seen in the past few years is mostly produced by immigrants and foreign workers and their families coming from ex-Soviet Union republics.
b. Russians that live in the big cities do not want to serve in the army as it considered a non prestigious job - a lot of the soldiers come from poorer rural families and from ex-Soviet republics. These days the Russian authorities are supposedly trying to reform the army - without any major achievements yet.
c. The numbers of Russian Muslims are growing due to the higher birth rates and constant influx of foreign workers/immigrants.
d. The Russian traditional Muslims are gradually being radicalized as a result of inner tensions and foreign influence.
The worst part of it all is that current Russian dysfunctional and corrupt social model can not adequately respond to those changes, instead they are often being ignored or disregarded as "natural" or necessary changes in society.
To sum up, I don't think that the Russian army would become Muslim in 2-3 years from now, the changes are fast but not that fast.
However, Russia is indeed fading away as a country/nation, culturally and socially for years now, and no one yet was able to stop that degradation.