Please update the documentation for internal directory with LDAP authentication to include a description and side-effects of checking the option Update User attributes on Login. Even though the UI has a brief description, this setting can often be overlooked if accidentally configured initially.

"User's attributes are updated from your LDAP server into JIRA when they authenticate. Selecting this means users can no longer be modified in JIRA"

It would be ideal to document how this setting prevents deleting users and how JRA-63697 may affect the intended functionality, leaving admins using this functionality with limited ways to disable/delete users.