This has been one of my fears about a country making bitcoin a legal tender. Bitcoin and Blockchain is so public that it can be traced by anyone. There's no way El Salvador will be secretly buying bitcoin without the knowledge of the public or IMF. Although if they so determine to do so, they will. I know the threat and battle to faced from IMF who threatened to stop borrowing them money if they adopt bitcoin. Why the sudden change and now the same IMF is disproving them of buying bitcoin.
Between El Salvador and IMF, if there's anyone to believe, I'll always believe El Salvador. Even though they don't buy more bitcoin as they claimed. That single act of bravery and boldness to adopt bitcoin when others were scared has earned them my confidence and they will continue to enjoy same as long as BTC lasts.