It would never happen, for a start the day the first DE FO on the pax fleet joined all three hundred SOs would instantly get bypass pay,,, not a cheap solution.
It sounds like a rishworth type company maybe getting a feel for whos out there, if there is a CX link it could possibly be for Air HK freighters.
Also why would CX mainline trust some others do do their recruitment, they have a large office with a number of experienced people doing the recruitment, and on the whole they do a good job.. maybe with the exception of hiring Wanchai Warrier