Just like anything that is left unmaintained, some of the apps in Apple’s App Store have begun to decay to the point where they no longer work properly. To address this, Apple said in 2016 that it was removing apps that hadn’t received updates in three years. Now, the company has announced that developers who have received notice about the removal of their app will have 90 days to update their app so they can keep it available for download.
Even if a developer considers their app to be feature complete, Apple and Google are continually updating their operating systems which means third-party developers have to then adjust their app, so messing with the code is something that needs to be done at least a few times a year to keep the app current. Under Apple’s rules, if a developer can’t give that much time to a project then they’ll have a three year period where they don’t need to update their app plus the 90 day notice period before the app is removed.
Before and after the news of the extension, Apple’s policy on removing apps is that they will only be removed from the App Store. Users who have downloaded apps to their devices will still be able to continue using the app. Apple didn’t say whether those users could re-install the app later, but presumably not.
If you create apps for the App Store, you should check the Apple Developer website which contains information about the new change including an FAQ.