Bitcoin can't be printed. It can't be faked. A record of all transactions is public. It crosses borders easily and doesn't require a vault. It is the perfect settlement for central banking transactions.
The BIS created SDRs to fill this role. Bitcoin might be that replacement.
What is needed is liquidity. An exchange in each country with a currency. Wealth translators to efficiently exchange Bitcoin for any other value, including gold.
To bind these currencies together a common language is also needed: Promise Language.