Do you have any more reliable information that would somehow support this claim? Other than this Facebook page, is this information somehow corroborated by more credible sources?
Anyway, it is not illogical if the IMF perceives that cryptocurrencies, I mean Bitcoin, could indeed displace local currencies of developing countries in the future. For one, these local currencies are weak. But such displacement does not mean the country is placed in a disadvantageous position. As a matter of fact, it is the developing country itself that would fully embrace the use of Bitcoin alongside fiat even if that could mean the demise of their fiat.