Bitcoin being a global currency in the future, no one can really tell. For now, I don't see possibilities that it will happen because majority of the country's government are still holding into their fiat and there's no way making it obsolete just because bitcoin's gonna take it place. Bitcoin may be more famous today because of its blockchain technology, but never will the government going to accept bitcoin as it only brings transparency, that any government won't definitely allow the public to know each transaction they make.