Yep. Interestingly while I was rummaging through the interwebs looking for answers I came across this article from July from ‘Which?’ about crypto payment bans and one of the things they said were:
Monzo didn’t respond to our request for information (although Monzo users did report blocks on crypto purchases back in April 2021).
So I don’t expect any more info beyond the pop-up in the app. Well, they can do whatever they like and if I don’t like it I can always switch the bank, I’m fine with that.