I don't want Adobe making the decision how far back to report on MY program. I want to see even previous versions that are running in the same workflow. Is there a workaround to deletions?
Delivery and tracking logs are only stored for 6 months by default.
If you want to extend the length these are retained, you'd need to speak to your CSM & TechOps to try and get this extended.
If it shows "Deleted" in the reporting, then the related delivery was deleted in ACS.
There is no automatic deletion of deliveries, rather a user has deleted a delivery in such case.