Resources imported by a Microsoft Active Directory Component import are not being deleted by the Active Directory Synchronization scheduled event.
ITMS 8.x
The synchronization schedule takes all resources pulled in by all Active Directory import rules and deletes them if they do not exist in the Active Directory (Unless it has become a managed computer then Purge Maintenance will do any removal). Because of this design, if a rule gets deleted, the synchronization schedule will not process the resources that were imported by it. The associations to the deleted rule need to be removed and the resources re-associated with an active corresponding rule. Then the Active Directory Synchronization will process the resources correctly.