I don't really think this will happen. It is too ideal, to begin with.
I concur with this opinion and the majority of responses. We would like Bitcoin to become a global reserve asset replacing the USD, but if that happens it will take a long time. It has some intrinsic characteristics that could allow it to be so in the future, such as its deflationary nature, but as of today it is more a fantasy than a reality. Would states and central banks have to buy Bitcoin for their reserves as well, for that to happen, and that is not likely to happen in the near future. .
The interesting part about Bitcoin becoming a global reserve currency would be that nobody could make Bitcoin that on their own. It would be the result of a common understanding that nobody suggested, but which Bitcoin causes everyone to gravitate towards with their opinions. It is not like there is a strong economy backing it (like in the case of the USD), but just the nature of how Bitcoin is and how it influences global decision making processes, it will cause nations around the world to consider it as a new global reserve asset. If that common understanding were to develop overtime, whether or not a single nation doesn't like it also doesn't matter. There is no choice but to accept it. Interesting thought experiments are imminent about this idea.