I am sure there will be no country that wants to use Bitcoin to replace the country's currency, but if there are countries that legalize Bitcoin as a trading tool, many countries have legalized Bitcoin.
All countries already have a system that has been built for a long time and it is not easy to replace a system that has been running well with a new one, even though it may be renewable, because it may be difficult to make rules. Better to stay as usual and allow to be able to use bitcoin for exchange, not as a substitute.