Originally Posted by
bocastephen
The upgrade is not a right or possession "given" to the OP. The seat remains the property of CO, and it's been well debated and determined here that if someone doesn't want their upgrade, they are to let the GA know so the next eligible person can receive the F seat.
You can swap with a spouse or travel companion, but not give your seat to a random person so you can sit in Y.
It's a new seat assignment. That's all.
All seats remain the property of CO, and if CO has a problem with me swapping with a person of my own choosing, I'm sure they'll let me know.
It may have been "debated," but in this thread, it sounds like you're down a few points.