I thought that too, and I thought the review was multiple governments back, but it seems one was done in 2023 with a recommendation to make the threshold 3.5% and drop to coat-tails rule (parties not meeting the threshold can currently bring in list MPs "on their coat-tails" if they get one electorate. E.g you get 3% of the party vote = 3 mps but you get 0 because you don't meet the threshold, oh but if you get 1 electorate MP now you are allowed all 3 MPs based of vote share. This change would mean you only get your electorate MP unless you meet the threshold).

Some other recommendations too, like lowering the voting age to 16: https://www.rnz.co.nz/news/politics/491390/electoral-system-review-recommends-voting-age-lowered-to-16-party-threshold-to-3-point-5-percent