Who cares?

I know this is a loaded question but I mean it seriously. The importance of legal aspects is highly varying, from matter-deciding to completely irrelevant. Especially if you have a government of a souvereign country like russia behind you, legal problems about redistribution or usage shouldn't be a big problem.

Microsoft doesn't really own the drivers. Microsoft just provides its DDK, then the hardware vendors who wish to include their drivers along with Windows are forced to provide the sources for the drivers in cause to Microsoft. Otherwise the drivers are usually made and provided directly, independently from Microsoft, by the hardware vendors themselves. Its safe to assume that the condition for using these drivers is something that has to make the hardware vendors happy (which is whatever sells their hardware).

Aren't the drivers for SAS controllers and other server hardware usually written by 3rd parties?

It's possible, I think, that there's some Windows driver SDK code used by most drivers that has conditions on it.