This effectively exists already in the form of paying third-party for a maintenance contract. Actually bumping the version number and repushing an app is the trivial part of being forced to do yearly (or w/e) updates - there’s a bunch of grunt work that can’t be automated in a trivial way - bumping your API targets, fixing anything that breaks from that, updating your build pipelines, fixing anything that breaks from updating your build pipelines, etc.
AUaaS - App Update as a Service