I know it always used to be...
One of the requirements for duty free entry of goods is that the owner 'has the intention of forthwith taking up permanent residence in New Zealand.' If you are not present at the time of arrival of your goods, Customs will take the view that you cannot at that time fulfil this condition, and the person you have nominated to receive your shipment will have to pay to Customs a cash deposit equal to the full amount of duty and GST which would normally be payable on the goods. When you do arrive in New Zealand, this deposit will be refunded to you, provided you meet all the conditions for duty free entry of goods.
From
here
.... so I don't know if it's changed recently. I certainly can't find anything on the Customs Site about visa status unless I'm looking in the wrong place. I assume what the above quote is saying is that, at the time your shipment is due to be cleared, you should have a valid WP or PR. I'm a bit puzzled by the 'you have arrived and on arrival hold a document authorising residence in New Zealand' clause, but I guess it would be right because, if you were a visitor or held a WHV or similar, you wouldn't/shouldn't be needing to import your stuff anyway. It's just a bit worrying that they tie it down to you holding a visa authorising residency when you actually enter the country.