DCMT VARY LOADLIB Vnnnn OFFLINE does not deallocate and so the loadlib cannot be renamed or deleted while OFFLINE.
This is by design.
The purpose of DCMT VARY LOADLIB Vnnnn OFFLINE is to logically VARY the loadlib OFFLINE from IDMS processing so that it can be condensed.
CA IDMS, all supported releases.
If you need to change the loadlib, for example from a PDS to a PDS/E or to rename it, this must be done across a CV cycle.