Am sure the countries have considered a stronger alternative and it would be wise to stick only the currency, abandoning USD influence in any exchange or trade within these countries.
Let me remind you that not a single state in the world will ever make its main currency, the "currency" over which it, the state, does not have complete, total control.
Bitcoin as a CURRENCY is not applicable for the economy. This has already been proven by countries that wanted to "save the economy" by making Bitcoin the legal currency of settlement or savings. A virtual asset that is not backed by anything other than wasted electricity cannot be a state currency and a measure of its economy!