Yes, once the events are aggregated (and optionally moved to a cost-effective storage for audits), we don't need them anymore in the primary storage. You can check the retention section in the article. The rollups themselves can have TTL if the users wish to set that on a namespace. Although doing that, they have to be fine with certain timing issues on when the rollups expire and new events are aggregated. We also have automation to truncate/delete namespaces.