Today, the Person Delta files pull in changes to IDs that are specific to a customer's universe. However, it does not also filter for fields in that customer's bundle - i.e., if an ID in the customer's dataset has a change, but the customer does not subscribe to the field associated with the change, the ID appears in the delta file, but it is unclear what has changed about the record.

By making delta files bundle-specific, all changes will be visible and relevant to the end-user.