Can we get an idea of how often this tends to happen?
I haven't been evicted from my favoured 62A so far, but I've got an upcoming MFU to CW on holiday with my gf and I'd hate to lose our selected 62AB out, 62JK back.
(seat assignments for leisure travel are far more valuable to me than for business trips!)
Maybe some frequent CW passengers (but perhaps not Prem/GGL as I guess you get shifted less) could post their seat-shifting experiences!