It will update to the same extent other fields update.
Ctrl+A followed by F9 will update them. You can just select and update as well.

You can use a keyboard shortcut for an AutoText entry.
If they know the name of the entry, AutoComplete will let them insert it with the enter key once they've typed the first four unique letters of the name.

I've updated the sample template to include a keyboard shortcut of Ctrl+0.