I also heard of that and saw in an article that some countries wants to legalize bitcoin by creating their own cryptocurrency that will governed by the government therefore taxes maybe imposed to all transactions. I think the root cause of this maybe it was alarming to the banks that in the future all their depositor will only save and transact through bitcoin because currently in bitcoin there are no central or middleman to all transactions so that low fees and penalties are more favorable than the banks.
If a particular country is going to create its own cryptocurrency therefore it will not be called as bitcoin anymore instead it would be altcoin and yes since it is the government who created that crypto then it will be easy for them to monitor the flow of the coin and easy for them aswell to impose taxes on the holders but then again its is not bitcoin and bitcoin holders are still free from taxes and can remain anonymous.