The Apple Push Notification service (APNs) configuration consists of the APNs keystore, which contains the Apple-signed certificate that is required to send push notifications to iOS devices. The APNs keystore is first created on one of the MDM Servers when the first APNs Certificate Signing Request (CSR) is created. When you import the Apple-signed certificate, it is first imported to this keystore and then replicated to the other MDM Servers in the zone, if any. Whenever a new certificate is imported, it would be imported into one of the MDM Servers and is subsequently replicated to other MDM servers in the zone. If MDM Servers are added or removed after APNs is configured or if the APNs configuration has changed, the latest configuration will be replicated on all the MDM Servers in your zone.
When the last MDM Server in the zone is removed, then the APNs configuration will be deleted entirely.