Navigation Block: Submenu's Parent Page is not marked as Invalid when page is deleted

[cuemarie]

Description

When a Navigation Block Submenu uses a Page for it's Parent menu item, and that page is deleted, the editor does not show (Invalid) next to the menu item, like it does for other menu items.

This happens with the Navigation Block in both Classic and FSE themes.

Step-by-step reproduction instructions

1. Add a navigation block to a site, and build a submenu with the parent item as another page of the site.
2. Publish the content
3. Delete the page that's the parent of the submenu
4. Refresh the editor where your navigation block is built, and the live site

Live site removes the submenu altogether, but the editor shows the same menu as before - without adding (Invalid) to the deleted page.

Screenshots, screen recording, code snippet

Screen.Capture.on.2022-10-06.at.17-34-34.mp4

By comparison, another page within a navigation block that is deleted shows (Invalid) added to the menu label:

Environment info

• WP 6.0.2
• Gutenberg 14.2.0

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

[stacimc]

I was able to reproduce this in WP 6.0.3, Gutenberg 14.4.0.