Surely if Monzo were to remove any personal account details from the card/switch up the design, they would just distribute the new version when someone’s card expired? I wouldn’t have thought anyone would expect them to waste money replacing 1.7 millions cards even for enhanced security (as the current card design used is still standard in the industry rather than being less secure than most other cards - I personally would prefer card number/CVC etc removed on future iterations, or at least optional).
Of course you could argue that someone may just say they’ve lost their card in order to get a new one sent out, but that could be said of any card redesign if it was seen in some way as being more desirable than the design that preceded it.
