That article is the only source I can find, and cites Max Keiser as their source…

I can find many other sources for the IMF having updated BPM7, their “statistics” manual to include cryptocurrencies. E.g https://cryptoslate.com/imf-updates-global-standards-to-include-crypto-in-balance-of-payments/

(I can also find sources in PDFs in the IMF website)

Sounds like another case of speculation/exaggeration