The listings file isn't included since this is really just copying the iso into it's final location.  The listings file is included in the ISO so we don't need the listings file and the iso to be published on the webserver.  This is covered by the pulp_rpm/plugins/test/unit/plugins/distributors/export_distributor/test_export_utils.py:TestPublishIsos:test_linking_http_iso_images test case.