Not sure what to make of this, but I booked a paid Virgin G seat (Delta marketed & ticketed) on LHR-ATL flight. I got an email from DL this evening indicating my flight # has been switched to a DL metal (but now Virgin marketed), and my seat selection is gone. The new select seat link takes me to regular DL economy seats.

I plan to call DL tomorrow, but curious if this is a common occurrence and how best yo approach it. I find the downgrade absolutely unacceptable. No reason has been provided, just an updated itinerary.