It guarantees nothing, but at the moment the sole refitted 777-200 is almost entirely dedicated to the AKL-HKG route, operating every second flight.
Whether the introduction of the next aircraft will mean the route becomes dedicated to refitted 777-200s is unclear, as it needs 2 aircraft to operate on the current schedule (which rather inefficiently leaves a 777 in HKG for over 12 hours a day).