Some further information here:
https://www.flightglobal.com/news/ar...petiti-455655/
It says that the codeshare only applies for through tickets to non-HKG destinations, not the purely HKG-Australia routes. But it doesn't seem to make sense. It seems that QF wants to make use of the CX network to fly to CX destinations such as India. So it sounds to me that this is more QF putting their code on CX metal, rather than the other way around.
CX putting their code on QF metal wouldn't create a through connection unless CX wants to sell itineraries such as HKG-SYD-CBR
Or capture the SQ clientele doing Australia - Singapore - India