We have four ways to show shortcuts according to this article:

Way 1: Select the help icon ? from the navigation bar near your profile picture, then select Keyboard Shortcuts.
Way 2: When viewing a page, press shift+?
Way 3: Press Ctrl + / (Windows) or command + / (Mac) when editing a page.
Way 4: While editing a page, select the ? from the bottom left corner of the page.

Way 1 and Way 2 show the same content and Way 3 and Way 4 show the same content.

The "Editing Actions" section on the page opened via Way 1 and Way 2 includes the shortcuts for how to move from Edit mode to Preview mode, how to move from Edit mode to View mode (Publish, Publish with note) and how to Find & Replace in Edit mode.

However, these shortcuts aren't included in the "Editor help" page opened via Way 3 and Way 4 specifically for Editing mode. The user can't get to know them.   

Suggestion

If the shortcuts shown in the "Editing Actions" section can be added to the "Editor help" page, it will help the users to find the proper information.