Hello,
Notifications are managed by the Notifications add-on.
Assignees and administrators will be notified when a post is created.
There’s actually no notification sent when a post is updated or a when a new owner is added, except if you check the “notify” box, on admin post screen, under the update button.

In this case, a notification will be sent to owners and administrators using the (File/Page/… created) templates that can be configured in Settings > Notifications > Templates.
Regards.
Want to help WP Customer Area? It only takes few seconds!
Rate & review the plugin on WordPress.org 🙂