I think removing the fiat and using crypto currencies are not a news, but more on speculation by some geek or socialist or economist that is looking forward to the future of bitcoin. Removing the fiat is really ridiculous, as you can see bitcoins are still converted to real money because bitcoin is not really known by many stores and they dont like its volatility. They are scared that bitcoin may end up making them really broke because of the unpredictable price. These is really far from happening because the government know what is these digital currency and what harm can it bring to its people.
Because cryptocurrency is the decentralized, and not can be controlled, of course using the cryptocurrency totally then surely it is dangerous, I can't imagine that the country's economy will be easily controlled if using cryptocurrency.
Legendariuscountry's economy controlled not only by money system, it's much more complicated