Typing in a name uses autocompletion which has nothing to do with your
Contacts or Outlook Address Book. It uses a separate autocompletion cache.
Nor does typing in the To: field invoke the Outlook Address Book as you
suggest. You are obviously doing something else to invoke it.
You can easily remove old or invalid references to Contacts Folders from the
Outlook Address Book view. Method has been posted here many times and
depends on your Outlook version, which you did not post. Just find one of
the posts that matches your version.