Last tested: Jul 15, 2020
If you have LDAP set up and then delete your old LDAP/AD groups in your IdP, you will still see the old group listed in the Groups page. For example,
Viewing Testing (Orphan 123456789) Group
It should be handled in the same way as SAML shadow groups, where the shadow groups will still appear until users from the old group re-logs in and gets mapped to the new group, or 30 days have passed.