If the user needs to get deleted when the user is shifted to a particular OU in Active Directory.
The advice is to change the permission of that particular OU, by denying the read access for the user who configured in the product for the particular domain.
Say, if "dk" is the OU allocated for moving the resigned users in Active Directory.
Say user "sample" is configured in domain configuration in the product, then restrict access of the OU "dk" for the user "sample".
So that while importing the OU "dk" is not accessible and the users in that OU will be considered as deleted.
Thus as a result the users in the OU "dk" get deleted from the product.
Below is the view of OUs in AD
Deny read access to the user "sample"
Configure the corresponding user "sample" in the product