As a retired BA pilot, I lose all my Staff Travel at the age of 89, i.e. my length of service added to my retirement age. This is, as I understand it the rule within BA, so a BMI retiree won't have any service with BA, consequently no staff travel. Since I probably won't make that age, it doesn't matter to me but it might to my wife. It also matters enormously to those ex BA pilots who retired after a relatively short career.
Nothing is fair in this world!