I don't think that Bitcoin will replace Dollar in the near future, but after 50 years or so who knows ? it is possible. Governments and most people nowadays keep using fiat as main currencies and it will need really long time to make crypto currencies as first choice for them.
Yes if bitcoin will replace dollar it may take sometime since fiat has been used for a long time and crypto is still very young but maybe the government is starting to study about this because will all know that almost everything now a days is bases in technology so maybe they are considering this to happen but then again it wont be that early maybe 50 years or more..