Expunging a user doesn't expunge their cluster accounts. Once a user is expunged, there doesn't seem to be a way to find their orphaned cluster accounts to delete them. Recreating the accounts doesn't regenerate cluster accounts, and also doesn't seem to reassociate the orphaned cluster account. When in this state the cluster accounts can't be autogenerated, instead the autogenerate action results in an error stating: The Username “xyz” is already in uses in this Unix Cluster