Is there a standard email notification rule to send to the Compliancereportedby person if it were to change?

Unfortunately, there is no standard field for this and the CHANGE criteria currently doesn't work for a custom trigger on compliance.

This standard field was developed to be based on 'REPORTED BY' (the person who created it initially) hence this would generally not change which is why logically it wouldn't make sense to have a standard email setup to send for a reassignment to this. However, you may have re-purposed this standard field to be a different role.