No, this won't happen. Why? Because Ukraine is highly depend from European and American transfers. Either the EU nor the USA has an interest that the blockchain or decentralized currencies replace known fiat money. if Ukraine would introduce Bitcoin - or any other crypto - and it will succeed, then people from other countries - especially where the economy is struggling - will claim decentralized currencies, too.
But the US or EU might make the Ukraine as an experimental place for the blockchain technology.