Somewhat related query. Just looked at some dummy bookings AKL-SIN in PE.
I hold TG*G and can always access the frequent flyer seats. However, on the 789 (both versions) the seat maps don't show any frequent flyer seating. No problems with the 772/77W on other dummy booking to HKG for example. I fiddled around with dates to find examples where no seats were allocated in the 789 PE cabin. [edited to add] Also, no problems accessing the Y frequent flyer seating on the 789.
So, has Air NZ removed frequent flyer seating in the PE cabin of the 789 for all *G/Koru HVC? If so, and despite the smaller cabin in one of the versions, this seems slightly odd.