Originally Posted by
paterwdb
If you are seeing that while in your itinerary, the seats are still available for sale, but not available for a paid upgrade. If you do a dummy booking not with the itinerary pulled up, you should see that D1 is available for sale.
But it is strange for an agent to say that the plane is "sold out". At the very least they should be able to quote a (probably insane) upfare price.
On-topic - I have seen similar things with D1 and also domestic FC cabins >100 days out (on flights I am booked in D1/FC) where nearly half the seats are unoccupied and unavailable. It is just such a weird thing to do - behind the scenes inventory controls determine what is for sale, not the seatmap. Why play games with blocking half the seats (other than crew rest or ADA seats) for those already booked in those cabins?