I traveled with two coworkers last night and one of them was able to secure an exit row seat (ironically, the one I vacated when I was upgraded to first class) via online checkin about three hours before the flight. She has no status. To my amusement, she was unhappy about her seat (10F on the 321) because the seat in front of her was too far away for her to store her various personal items in the seatback. She was quite pleased to be in "Zone 1"