The Filr readme has this to say about the "delete users not in ldap" option under LDAP configuration.

6.5.1 Issues When Deleting Users through LDAP

Novell recommends that you never select the option Delete Users That Are Not in LDAP when configuring your LDAP synchronization. This feature will either be enhanced or removed in future Filr releases. User accounts that are deleted cannot be recovered. As a best practice, leave this LDAP option unchecked. Doing so disables users rather than deleting them.

What is the story here? We are a K-12 District and add/remove thousands of user accounts every year. My assumption would be that it would be good to remove them from the Filr db once they are purged from ldap. Why does Novell make this recommendation?