The last time I experienced changes in assigned seats is HKG to TPE flight. CX is really playing musical-planes: every week our family of 4, which originally assigned together, are bounced around like ping pong balls when they swap airplanes. All on different rows, despite the fact I told MPO to link us together and 3 of them are on the same itinerary except me.

Luckily I have never experienced being booted off a seat myself, but I have inadvertently booted someone off a seat when at check-in the agent asked me: "are you happy with your seat, I can give you a better one", I was sitting in the back rows aisle, and she made a call and put me in first rows window, the seat I wanted. So I guess CX does play favorites....