Uploading entitlements attributes via a CSV will not mark it as privileged.
You can Use an Entitlement API to update the privileged attribute or edit it from the web ui to mark to override the privileged option :
Once specified, the privileged option is set to true.
Sailpoint has recently released new feature regarding entitlments privilged management New Capability: Privilege Classification in Identity Security Cloud - Announcements / Product News - SailPoint Developer Community which can be con figured also at source level.