Neither bitcoin nor paper money has any real value, but notes have national credit support, and what if bitcoin also gets national credit? The government will lose its macro-control policy but it can also effectively eliminate inflation, two relative ratios. Is that a good result? Of course, I know that the government is very unlikely to support bitcoin, but who knows?
if the Government support only the Bitcoin instead of other currencies then their economy will fully changed into Bitcoin system this is probably good and bad filled with both positive and negative we cannot be very sure about how it is possible but if it is possible then the good changes is also available.
And I believe that negative things will be bigger than positive things when the bitcoin community is too small while the user community using cash is too big, therefore, with sudden change and unexpected support from the government, many people will be hard to accept this truth. A more annoying thing is that the community will become chaotic when converting the trend of daily currency trading, they will be embarrassed not knowing whether they should choose bitcoin or available currency, the economy will be delayed for a while