This is terrible. I asked one month ago and was told yes, it would be possible, and was directed to this statement by Monzo saying it would be:
I see now the statement I was directed to was from February, but it is what I was shown when I asked only one month ago.
I will need someone from Monzo to revert me to the prepaid card so at least I can continue to use it while that service exists, which I gather will be a little longer at least. I guess it will be better to contact them via help or similar rather than forum.