If you are using an SMS-managed robotic/virtual tape solution, then the ACS routines would assign a MGMTCLAS, STORCLAS and STORGRP for the tape dataset. If it was not SMS managed however, you wouldn't get past DATACLAS for tape datasets. However, the SMS MGMTCLAS that CA 1 currently obtains is NOT the same MGMTCLAS assigned during ALLOCATION processing (though it might be) because currently we drive our own call to ACS passing those parameters allowed by IBM (which is a smaller subset of the parameters passed via the ALLOCATION call to ACS).
However, we are finishing an enhancement to CA 1 to record the ALLOCATION-assigned MGMTCLAS in the TMC for SMS-managed tape devices. Is that something you might be interested in testing?