I can disclose a bit that it is normal practice to buy a FreeDOS or Linux license(s) for any company in Russia, even for state-owned like high schools, and still use ms-windows on a regular basis. So it's only a visibility of Linux wide-spreading in favor of cost cutting, which is simply the modern business paradigm with nothing related to reality's technical details.
Tatarstan is the subject of Russian Federation and actually is the same way independent as any other one.
More to say: sovereign independence of Tatarstan is the thing both impossible because it has no any outer state borders AND inevitably should lead to total destruction of Russia which is not the case to happen.
As a fact, the "pilot education program" about FOSS is the Alt Linux disk set packaged with a book for schools, is performed in several regions of Russia, Tatarstan is simply among them.
I even know someone in person from altlinux moscow based development team who is originally from Tatarstan.
Hope this is a fix to correct the info.