Very odd decision given they have come up with a plan to base a large number of A320 Neos fitted with just business class seats in HK to feed into China.
I believe the new carrier is supposed to be based in SIN:
Qantas Singapore Plans May Be Blocked | AVIATION WEEK
Having said that, you'd think that the additional demand out of SIN (due to the new carrier you mentioned) would increase the need to carry pax via HKG, rather then decrease it. I believe that QF29/30 could have functioned as the primary Asia-LHR flight for PER and BNE pax, thereby allowing the SIN-LHR A380s to cater for the new QantAsia in the manner you suggested.