They cannot stop El Salvador and Bukele for doing that. Look at the news that came out, since March they've bought a total of 13 Bitcoins already.

And just recently, they've bought 5 more Bitcoins. So, with IMF telling them to stop, I don't think that they have ears for that.

Good thing that the fund was already released on them and Bukele can do freely whatever they can do with that loan.

--> https://cryptonews.com/news/el-salvador-acquires-additional-6-bitcoins/