My god,
these type of agreements wont be in writing!
The only way you will get them if either a CP/CEO admits it OR someone from HR etc has enough balls to expose it?
Either way it wont happen, I have no doubt that some form of agreement exists at small points in the hiring cycles/expansion of an airline, but agree that if its a large intake and only candidates from one particular airline then they will most likely get the call up.
I still wonder at this exact same scenario for myself when I see MANY pilots go to airlines that I am on hold files for!
Easy solution to that, get on other hold files