No way am I going to trust what the IMF says on this issue. If they have really been buying it and keeping it in cold storage, it's very easy for them to prove it. The purchases are managed by Stacy, Max Keiser's wife, who I hope will respond to this accusation soon. Although I wouldn't bet my life on it either.
The IMF hates bitcoin because it takes power from them so it wouldn't surprise me at all if they are lying about it. Their credibility - both with regard to bitcoin and economics in general - is zero.
There could be ways to verify what both are saying and this is what is good with blockchain tech, right? They can't just manipulate proof because anyone can verify for themselves. But right now, there are so many uncertainties going around. El Salvador remains to be genuine about their bitcoin journey though since they are the ones who first took the risk and made bitcoin legal tender anyway.