The golden days at AirNZ have long gone. Expect to be an SO or 320 FO for 20 years. Thats the cold hard reality. Some junior drivers are looking to leave Air NZ for that reason. Don't like it? Leave. The system won't change any time soon. There are some pretty bitter people out there.
Anyone hanging in the wings on an illusive "yes letter" should look at Pac Blue or Jet Star. At least the hands on time is recognised by EK which will give you the option to move on. AirNZ SOs don't really have that option.