How will it help New Zealanders if they just invest in real estate? Seems like a good speculative bet for them, but mostly it just makes it more difficult for young people to get afoot in the property market....
This is how the free market works, in general. When prices go up, it incentivizes asset creators create more. This is one of the down-sides of zoning limitations - they do not let the market provide more for the additional demand.
...and a simple Google search confirms that NZ has been experiencing a construction boom.
The kind of houses which locals are priced out of due to low wage economy. Certainly good for wealthy immigrants and cashed up Kiwis returning from overseas though.