Well, this is sort of a kick in the pants.
One of iOS 9’s major new features, App Thinning (or “app slicing”), has been delayed due to an issue with iOS 9. App Thinning was announced at WWDC as a way to help trim down the size of large applications by letting developers mark assets for each specific type of device. When users download the app, the App Store will determine which device they have and only require them to download the assets necessary to run on their device.
Although App Thinning has been examined in TestFlight for the past few weeks, Apple has said that App Thinning will not appear until the company resolves an issue in the way iCloud handles backups.
The issue was explained as follows:
App slicing is currently unavailable for iOS 9 apps due to an issue affecting iCloud backups created from iOS 9 where some apps from the App Store would only restore to the same model of iOS device.
When a customer downloads your iOS 9 app, they will get the Universal version of your app, rather than the variant specific for their device type. TestFlight will continue to deliver variants for your internal testers. App slicing will be reenabled with a future software update. No action is needed by you at this time.
This could explain why assorted app updates have been reissued through the App Store.
App Thinning will continue to function on TestFlight without any changes, but developers will not be able to distribute sliced versions of their apps on the App Store until a software update fixes the issue.
Stay tuned for additional details as they become available.
Via 9to5Mac and Apple Developer Center