I haven’t read the whole thread, to be honest I couldn’t be arsed.
You must all know that I never defend BA when they are in the wrong but I am 100% sure there is no seating preference given to staff, everyone who has access to seating is watched carefully and would risk losing their job for something so obvious and not important.
I truly believe these seat changes occur due to configuration changes and operational problems such as technical problems with the seat that is then fixed by our engineers and put back for allocation.