The versions of the app that are currently working for MPC (and have been working this year) will continue to work unless and until there is a substantial operating system upgrade with which the now-working versions of the MPC app becomes incompatible.
I say this because when it comes time to go for say an iOS upgrade, at some iOS upgrade point the iOS app versions being used currently will no longer work even for those who haven’t updated the MPC app at any point after the first quarter of this year. For those who keep an older device as a relatively clean, quasi-disposable device for cross border use, there are ways around this app-disability from eventually hitting.