Out of the box ActiveRoles does not include the ability to query deprovisioned users in a DG or a MU.
A MU can contain deprovisioned users if the rule "Retain deprovisioned" is used per the following information from the ARS Admin Guide page 48.
The Retain Deprovisioned rule is intended to adjust the behavior of Managed Units towardsdeprovisioned objects, such as deprovisioned users or groups. Once an object is deprovisioned, the default behavior is to automatically remove that object from all Managed Units it was a member of. If there is a need to keep deprovisioned objects in certain Managed Units, you can satisfy this requirement by adding the Retain Deprovisioned rule to those Managed Units. This rule causes the Managed Unitto include both the regular and deprovisioned objects that meet the membership rules for that ManagedUnit. Without this rule, the Managed Unit does not include any deprovisioned objects.