We set up our subscription to delete items that are 1,190 days old, this Workspace change was done a couple of days ago, however, items that were deleted more than 1,190 days are still showing in recycle bin.
This page has details about how to set this functionality up: https://techdocs.broadcom.com/us/en/ca-enterprise-software/agile-development-and-management/rally-platform-ca-agile-central/rally/administration/managing-your-workspace/customizing-a-workspace.html
There is a job that runs to delete these recycle bin artifacts every day for all subscriptions. If there are a lot of artifacts to delete, it may take this job a few days to get through all the backlogged artifacts.