This was first announced a while back. However I'd rather they increase the business class cabin (admittedly tricky layout issues). When they refitted the premium cabins offered less seats than previous (when it was first and business class) and NZ took a conservative approach due to the need for a single config for each a/c type.
On several routes it can be hard getting paid full fare business class, so IMHO it wouldn't hurt to have a few extra seats even if on some routes there isn't quite enough demand.
I can't remember the last NZ longhaul flight I have taken on 747 or 777 that wasn't full (or just 1 spare seat) in business and premium economy, no matter if economy loads light or full.
Trying to access your favourite Australian websites when overseas only to discover they have been geo-blocked? Concerned about your internet privacy especially when using unsecured wifi? NordVPN will solve both these common problems.