Originally Posted by
star_world
I think that's about as unlikely a scenario as I can imagine - clearly you disagree since you chose the word "likely". I've had family members in this situation several times and upon arriving at the airport they either (a) already had a seat assigned by the kiosk, or (b) the agent handed them a boarding pass without any discussion.
Murphy's law doesn't always apply - at least not to everyone
The scenario becomes more likely as more planes get E+. Particularly on light Elite routes. I don't know where you're flying, but this sort of thing is common, especially when someone finds themselves in the situation the OP describes.