We've noticed is that some of our Groups have been automatically given this new Global right "Status Report - Delete All" after upgrading.
Do you know in what version this new Global Right was added to Clarity?
This right was introduced in Clarity 15.9.2. Previously the "Edit" right gave users the ability to delete Status Reports as well. This functionality has been separated into a different right. If users had the Edit right, they would have the Delete right after upgrade.