Plato
I had the same problem with my upcoming trip to SYD. AA tried to get me a hotel room due to a forced overnight. CX responded no! I then called CX directly and spoke to a supervisor - 4 minutes later I had a choice of hotels in central or the airport.
Give calling CX directly a try.
BTW when are you passing through HKG fom/to SYD? I will be there June 6 &9