Alternatives to MMP will not necessarily reduce the ability of Maori to get into parliament:
Since its introduction in 1996 MMP has meant “More Maori in Parliament”. It is the best system, of those on offer, for Maori representation in the New Zealand parliament, says Maori politics lecturer Dr Maria Bargh.
On the contrary, in an excellent post fact-checking the referendum Graeme Edgeler writes:
Under MMP there are currently 7 Maori seats. A change to first past the post, or preferential voting, or single transfer vote systems would see an increase in the number of Maori seats to at least 12, and probably 13 seats. A change to the supplementary member system would see an increase at least 9 and possibly 10 Maori seats.
Any voting system which has more electorates will result in more Maori seats. Regardless of the system Maori will also have as much a chance as anyone else of seeking a general electorate seat.
Maori seats aren’t up for debate by the Electoral Commission should a majority of people vote to change from MMP but that doesn’t guarantee they will remain.
Abolishing them has been National party policy for a couple of elections but dropping that was one of the concessions the party made in coalition negotiations with the Maori Party.
I have no idea what National’s policy on the seats will be for the coming election but it’s a sure bet that Act will campaign on getting rid of them.
If National is able to form the next government and Act has a role as a coalition or support partner and the Maori Party doesn’t, the Maori seats will almost certainly go.