Yep, think status played its part here - oneworld sapphire (Cathay). This has never happened to me before either! I can't think of anything better in the world than an unexpected upgrade, so I was pretty amazed . Although, I will say I seemed to be getting special service from QR whilst at the airport in ARN. They rang me super quickly after I messaged their Facebook page originally, letting me know the situation. 20min later I messaged the FB page again to ask the reason of the delay, and the same agent almost instantly called me to explain. Another paid business class passenger overheard me on the phone, and asked how I got them to call me - as he was missing a connection as well. They only called him 20min later...

I've only flown QR once before, in Y. So this was all pretty surreal.