Yes, but the federal government uses far more than just Office.

Microsoft is very far from being at risk of failing, but if it did happen, I think it's very likely that the government keeps it alive. How much of a national security risk is it if every Windows (including Windows Server) system stopped getting patches?

Not sure if this is a real question but yes, I think Microsoft is too big to fail.

honestly I think of Microsoft was going to go bankrupt they probably would get treated like Boeing, yeah.