I'd say its just the opposite. It's anti-competitive practices from MS. They're trying to build their own walled in hardware/software garden. It would make more sense to me if MS was blocking Google stuff, not the other way around.

They probably figure if they let Google in on some things, then they open the door to supporting all of Google's apps like gmail, chrome, calendar, google docs, etc. Which goes against them wanting people to use outlook.com, their calendar, MS office and IE as their main browser.