El Salvador probably wanted to keep their image as a bitcoin friendly country. Not only do they want to appear friendly to bitcoin, it seems like they want to be a country known for having a lot of bitcoin and possibly get investors in their country. I have seen some people doubt IMF's reports but what do you think? It makes sense if bitcoin has become El Salvador's political move.
I read the report too and I think IMF has no reason to lie. El Salvador clearly have been lying and deceiving everyone by moving bitcoin from one of their address to another to foul people into thinking they're still actively buying Bitcoin. They know the consequences for breaching the agreement with IMF and they don't intend to go against it.