After a number of clueless Delta agents, I finally got someone who managed to fix my itinerary. She rebooked all 5 in Upper Class on a VS flight that shows "sold out" on Delta website. Delta reservations have been updated, but seat map is not available. When I check VS website using Virgin booking number, the itinerary is still the old/overlapping one.
Does it take time for Virgin to sync up with Delta changes?