I doubt this is an issue of formatting. The airline has to file a list of aircraft with the aviation authority and they would all be in the same format, and the flight plan would be too. I suspect nzkarit’s second explanation is the likely one, or that NZQ is sufficiently new that approval hadn’t yet been given by the Chinese, and someone in Air NZ ops stuffed up when NZQ was assigned to do the PVG service without this being flagged,
It’s not an issue unique to Air NZ; I know of one Middle Eastern airline that ended up with a 777 stuck in Africa for three days because the aircraft wasn’t on the local approved list, and it wasn’t picked up until after the plane landed and was about to fly back to base.