Although Microsoft is a backer of Ethereum, Microsoft will likely release new iterations of Cryptocurrency that are able to handle national scale transactions.

National adoptions of cryptocurrency need to have tens of thousands of transactions per second or more.
Nations will need a massive developer community and active software development.
Although Microsoft has had its issues in the past, they have experience enabling a large software development community.

Nations will likely each adopt their own cryptocurrencies. They will not ultimately depend upon Bitcoin. There is too much baggage and technical issues with Bitcoin.