Had a weird one last week: ORD-DTW on a 738.

Seat map showed only 1 out of 16 seats occupied, but EF showed F2 Y7 a few days out, then F0 Y1 24 hours out. Thought it was strange that so many F pax had unassigned seats, but I guess it's possible.

Not sure if this was an inventory management screw up or what, but 15 upgrades (including wife and myself) cleared at the gate.