You can set notification based on Audit logs entries with High alert which will describe the changes in ePO console.
Thank you for your reply ansarias, but I'm not sure that this approach is sufficient. Audit Log categorizes deleting a 'Client Task Assignment' as a 'Medium' priority event, for example, and removing an assignment from 10,000 inheriting nodes might have a critical impact.
The more I think about this, the more I don't think I'm going to be able to do much. Maybe if ePO logged greater details like 'Assign task "Bleh" to node "MyOrg" affecting 9978 managed agents' there would be something to work with. Probably wouldn't work well there either, it would probably have to be a new field in the table.