I flew on CX 713 today from BKK to SIN (a two-class 777). I was on a very cheap coach ticket priced ex-BKK. I have no status on CX or any of the One World Carriers.
I checked in and was handed a business class boarding pass because the flight was oversold.
So from my perspective, it's great. Now if I was a full fare business class passenger who lost his seat to me...
(And no, I'm not Thai and had no connections with the agent)