I think this would be a really good feature, considering the fact that some migrations are being scheduled for Friday after working hours and some customers are waiting for an update (which sometimes can happen 2-3 days later - on Monday) regarding the migration process before they continue further with the POST migration steps. The idea of the customer being notified as soon as migration has completed successfully is to save some time, which our customers can use to complete the post-migration steps without having to wait for support to reach them first thing in the morning (especially after a couple of days have passed).