Last year, the Make It 16 campaign took the government to court, arguing that the government's restriction of the right to vote to people over 18 was discriminatory and therefore a breach of the Bill of Rights Act. They lost, but only because the judge didn't actually engage with the question and fell back on tradition. Today, the Court of Appeal ruled on the inevitable appeal, and found that the voting age is discriminatory, and that the government had made no effort to justify it to the standard required. However, it declined to issue a formal Declaration of Inconsistency.
(Along the way they also held that the BORA's interpretation clause applies to the BORA itself, which is useful caselaw for the future).
This is a pretty big victory for Make It 16, and it puts the onus squarely on the government to either justify its voting age policy or repeal it (obviously I'd prefer the latter). The obvious vehicle for that is the upcoming electoral law review, though that won't see it fixed until the 2026 election at the earliest. A better path would be for the government to simply accept the ruling and legislate next year, allowing 16- and 17-year-olds to vote in 2023.