The description of PTF LU09382 states:
In order to track usage of entitled features of Top Secret, support is required in the ESMs to register the product using the new CCS #REGPROD common service. The product registration service leverages the relatively new z/OS service for tracking vendors, products, and features. This enhancement is to implement the Product Registration Service in Top Secret.
If the ESM services are not currently being used, is it mandatory after LU09382 applied?
Release : 16.0
No. It is not mandatory to use ESM services after LU09382 is applied.