Also, I don't see why any foreign country would legitimize bitcoin. With the debatable exception of Ron Paul, people become politicians so they can enjoy political monopolies. Bitcoin is destructive to that end.
Some countries have pegged their currency to the dollar. Others see the dollar as a threat.
That is because some countries are powerful enough to assert their own political monetary monopolies, while others lack such power, and their political classes are content to be parties to the benefits of the US monopoly. There is
no political advantage to a nation adopting bitcoin. That is its best quality. I can see it being possible for a conservative monarch of some kind to use it in a misguided attempt to be a "laissez-faire ruler", but only theoretically.
What could be more likely is that a smaller polity might adopt it in the process of secession from a larger state (say, the Canton of Zug from Switzerland, for example) but even that likelihood seems marginal to me. And the US, as history shows, is rarely very friendly to secessionists. We can be nearly certain that if a US State were to secede with pro-liberty motives and use bitcoin, that would only solidify the Federal government's position against it.