Systems and methods for optimizing storage and retention of deduplicated secondary copies at storage platforms that are write-once read-many (worm) enabled

A computer-implemented method comprising:

• by a first computing device hosting a storage manager, wherein the first computing device comprises one or more hardware processors and computer memory:
• providing a user interface for administering a storage policy comprising one or more write-once read-many (WORM) options for storing deduplicated secondary copies generated by a data storage management system from a source of primary data;
• causing a storage bucket at a storage platform, which is WORM-enabled, to be configured according to the one or more WORM options administered via the user interface;
• executing a first plurality of deduplication copy jobs based on using a first deduplication database (DDB), wherein a second plurality of deduplicated secondary copies, which result from the first plurality of deduplication copy jobs, are stored into the storage bucket;
• sealing the first DDB based on a DDB sealing frequency;
• and
• based on the first DDB having been sealed, and further based on the storage platform releasing a WORM lock on at least one of the deduplicated secondary copies, initiate pruning of the at least one of the deduplicated secondary copies from the storage bucket.