I wrote a letter to TTU to this effect, for one time I got moved from the exit window the the VERY back of the plane in between two people because of an equipment change.

I made the suggestion to notify pax of equipment changes and pointed out that many people get elite for the strict purpose of getting good seats in front; if they're just going to get shuffled, elite status loses its value.

Got a canned response saying "tough luck, buddy".