From the papers they released, I don't think they are. But this is an institution that works with SDR [https://en.wikipedia.org/wiki/Special_drawing_rights]; so they are not going to "understand" Bitcoin. In a sense, they have their own Bitcoin.

And I put understand in quotes because the IMF does get Bitcoin, Crypto and finance better than most countries. They understand that crypto is mostly bad news for weak countries because they are already having trouble with capital outflow as is.