When a Moodle site URL changes what usually happens is that users are not able to connect to the old site anymore and they are presenting with a reconnect screen, this screen usually don't work as the old site is not available anymore or is implementing a redirection to the new site not supported by the app. Mobile Push notifications will stop working as well as they will include the new wwwroot as part of the payload and Airnotifier won't be able to properly deliver them.

We should try to find a way to allow site admins alerting mobile app users about this so the app can do some work behind the scenes to re-connect users to the new site.