I tried looking for this on other threads and didn't see anything relevant. Does anyone know what the guidelines are for F9 as they relate to forcing changes to seat assignments that have been locked in as advanced seats during the ticketing process? I've had several istances now where I've had aisle/window exit row or stretch seats booked during ticketing(all airbus flights) and at check in, seats were changed to any number of other rows and positions outside of exit row and stretch. The party line I hear is equipment changes cause seat change assignments. I only fly routes on F9 with airbus models(318/319/320) have the same number of extra leg room exit row seats(6...usually row 10 for me) and stretch(24 seats). I love middle seats as much as the next person, particularly after having booked much more agreeable seat locations.

1. Does an equipment change really force them to move my seat location, particullary if I have an exit row or stretch seat or are they bumping me out to give preference to someone else?
2. Is there a method to madness as far as seat change reallocation?

Thanks for the help.