When will "apns-push-type" header be enforced?

Hi,


We have been sending standard (non-silent) push notifications to iOS13 devices without the "apns-push-type" header and it still gets received by iOS 13 devices.


The app was built using XCode 10.3.


When will the absence "apns-push-type" header prevent the notification from getting received?

Is there documentation about having a grace period before this really gets enforced?


Reference: https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/sending_notification_requests_to_apns


Thanks.