warren9 will explain
AC doing BNE/YVR will steel marketshare from NZ (many ex BNE pax want to avoid awful SYD like the plague) & also some of those flying BNE/LAX/YVR.
Only thing is many want their QF ff points & many families actually want to stopover in LA & you can use Qf ff pts to fly LAX/SEA or to various ports in Canada.
Those who want convenience will fly nonstop.
NZ from memory, used to codeshare with some AC flights(both are star alliance), so expect some tie up.
The other interesting bit, is AA/QF talking about LAX/AKL which will also impact NZ.