A few months ago it was rumored that Apple would begin to draw from the App Store those old apps and were rarely updated, because the purge already launched.
It seems that the company iron is held in position to make the App Store a store where your applications are updated daily, but still, many developers are not happy that they removed their old apps from the store, more lies continued operation.
To keep your applications on the App Store, Apple is encouraging developers to submit updated for review within 30 days versions.
After 30 days, remove any old application Apple Store "until an update is submitted and approved."
Any removed application will remain fully functional for users who have downloaded before disposal. Users will not experience interruptions in services as it still will be able to make purchases "In-App" (from the application itself) and may re-download a copy from iCloud or iTunes.