Seen this happen many times and have yet to see an FA decline a pax' request to move. Also seen other pax seated next to the empty seat argue with the FA, only to get nowhere.
If they offered onboard op-ops like some airlines, I'm sure they'd (possibly) be more inclined to protect it.
Originally Posted by
ShortDog
That's why I usually put my stuff on any empty seat next to me.
+1. This is the only way to semi-guarantee the empty seat.