You are lucky you were able to keep a bulkhead aisle.
I just noticed we were booted out of row 3 aisle-window on one of tomorrows Airbus EWR-LAX flight and into a middle-window in row 9. There is no row 3 now. Bulkhead is row 6.
Reservations were able to move me into exit row aisle, but my wife remains in a now-crappy window seat.
The problem with the airbus is that until they retrofit the interior, only the bulkhead seats offer more legroom.
The algorithm for automatic seat reassignment is not very good and there's, of course, no notification that it happened.
-David