Open Radar

 
CloudKit zone subscription requires push notification to function properly, that is, to receive a notification each time the zone is modified. This allows fast and energy efficient way of synchronizing data from CloudKit servers to the device.

However, this CloudKit notification is treated in the same way as standard notifications: they can be disabled from the settings by the user. Users can disable notification from an app because they don't want to be interrupted when using the device. Lots of users do that. But in this case, it also breaks the CloudKit mechanism (without the user even knowing it).

It's suggested to implement a fallback mechanism based on CloudKit polling. That's technically possible, but it's very hard to explain users that they need to enable notification for the app to have a more efficient syncing. These are unrelated features to the user.

My suggestion is to allow those UI-less sync notifications for apps relying on CloudKit zone subscription, as an implementation detail. Users opting for CloudKit should get the best possible experience, without having to consider enabling notifications from app's settings.