I haven't run into this before. Just booked Mrs. Gargoyle ORD-ATL, mainline DL metal, flight is more than a week away. Seat map is all blanked out, no seat assignment. I called SMS, they said the flight is now sold out, there are 23 seats available which are being held out for assignment at the gate.

Isn't this pretty far in advance to block them all? Have you seen this happen? Any chance they'll open up before check-in? (in other words, should I log in every day and check, or just give up and get to the airport early that day?)

Since she's currently FO, I suspect this means that upgrade chances are not good.