I don't understand why they had to move the body at all. She would have had a seat, the one in which she sadly died. Why did they move her from it only to place her next to somebody else?
Equally, I wouldn't find it that unsettling myself but we're all different.
And yes, he could have asked to move. Or just don't ask, just move.
Perhaps to the deceased's original seat, which by the sounds of it, was now going spare...