It would be silly for central banks to not be accumulating some Bitcoin just in case. They understand how money works..
There is so much we do not know about, so I think your right, it would foolish and strange, if the government didn't take part
This is between bitcoin and goverment to come to agreement ,if this cryptos will be accepted and adopted by the different governments all over the world ,then there are big possibility that banks will really adopt and accept bitcoin, because banks are facilitator and keeper of currency ,so if bitcoin will be legalized then bitcoin have a space in the banks.