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

A data storage management system comprising:

• a first computing device hosting a storage manager, wherein the first computing device comprises one or more hardware processors and computer memory, and wherein the first computing device is configured to:
• provide a user interface for administering a storage policy comprising one or more write-once read-many (WORM) options for deduplicated secondary copies generated by the data storage management system;
• cause a storage bucket at a storage platform to be configured according to the one or more WORM options administered via the user interface, wherein the storage platform is WORM-enabled;
• initiate a plurality of secondary copy jobs associated with a first deduplication database (DDB), wherein the plurality of secondary copy jobs generate a second plurality of deduplicated secondary copies and store the plurality of deduplicated secondary copies into the storage bucket;
• determine that a sealing interval for the first DDB has passed;
• seal the first DDB based on the sealing interval having passed;
• based on determining that the first DDB has been sealed, deactivate the first DDB and cause a second DDB to be activated in the data storage management system;
• and
• based on determining that the first DDB has been sealed, and further based on determining that the storage platform released a WORM lock on at least one deduplicated secondary copy among the plurality of deduplicated secondary copies, initiate pruning of the at least one deduplicated secondary copy from the storage bucket.