Yes, they will.
Even the official bank of China will release its digital currency.
But that's barely currency, have much difference compared to the ones we discussed.
This is what will start happening gradually and eventually. Most countries are already getting aware of the future of blockchain technology and the next thing right now is to see how they can make it a possibility for them to be able to integrate it into the monetary system so they can benefit from it. A time will come when unnecessary printing of money will pass, and then we will get to see a lot of development coming up for most countries with the use of the blockchain.