At least that is true for the NZX50. I haven't found any sources for the other minor NZX indexes that the S&P maintain:
S&P/NZX 50
S&P/NZX 20
S&P/NZX 15
S&P/NZX 50 PORTFOLIO
S&P/NZX SCITECH
S&P/NZX 10
S&P/NZX MIDCAP
S&P/NZX SMALLCAP
S&P/NZX ALL
S&P/NZAX ALL
S&P/NZX MORRISON
NZX still reveal the constiuents of other indexes:
PRIMARY
ENERGY
GOODS
PROPERTY
SERVICES
INVESTMENT