Ability to replace an AppSheet based app on the Google Play store with one that isn't

Context: I’m a Publisher Pro user and I’m happy with the AppSheet platform.

My request is mainly to do with guaranteeing the longevity of an app listing in the Google Play store. What I mean is, is that if its decided that AppSheet apps can no longer be published to an app store for public use that we can have the keystore so that we can replace the AppSheet generated app without losing the user base, for example. It seems that since subscribers have control over the certificates for the iOS version that this isn’t an issue.

Since AppSheet is part of Google now it should be possible to upload the original keystore to Google Play and support App Signing so that updates can work without the original keystore (but correct me if I am wrong). The steps would probably look like this: