Same, which is a shame cos there's a lot of potential there but I can kind of see why as there's so many potential answers to the premise that it becomes a lot to consider; still I'd love to see it explored and do have some thoughts on the subject.
1: Is "New Zealand" still created?
If so then there's probably a couple of ports on the continent, but they'd not be designed with expansion in mind and likely be a sort of 'resigned to Siberia' thing, a few dozen people, a shitty barracks and supplies, plus fishing equipment and poultry. This would lead to much slower, more drawn out contact and interactions that would be heavily reliant on the local port and whoever sneaks off the ships or gets cast out for one reason or another.
2: Assuming "New Zealand" isn't a thing
The continent would by and large be avoided by European powers, its winds aren't favorable, its coast is rough and they don't think there's anything or anyone there of significant worth. However, this wouldn't stop
Makassan sailors or others from sailing down to trade so long as the market for Sea Cucumbers didn't dry up, so that creates an avenue for bleed through of materials and ideas from the rest of the world, if a small one.
Aside from that, I imagine the continent becomes sort of a refuge for "scoundrels" and the like who are well bottom out of luck and are now just trying to not die, and also a bastion for criminals or even revolutionaries to hide out. Plus there's of course missionaries, both Islamic and Christian, however neither of these would have much if any government backing so I doubt they'd meet with much success so much as be regarded as obnoxious and pushy interlopers as it wouldn't be the skilled evangelists going.
3: If an attempt had been made or considering point 2
Then I would say some livestock like Water buffalo, pigs and horses may well have ended up there and likely either causing problems, or becoming beasts of burden to the indigenous population, likely a mix of the two. Sheep & poultry wouldn't last however. Besides that, a combination of leaked ideas, tools and trade, along with local ingenuity, could definitely see internal changes coming about, especially if a colonization attempt had been made, or simple visits and disease disrupted local systems and power structures enough to cause really intense waves that could lead to cascading changes.
4: Long term, I am unsure the continent and people would be ignored forever, forever, its a lot of land if nothing else and around the World War 1 era Japan at least was desperate to join the "big boys clubs" of colonizers and might start simply so they can say "Look I'm a big boy too!" though likely only once done wit Korea unless butterflies from these past even caused that to be less tenable.
Those are just some off the cuff thoughts however and not even close to the width and breadth of potential that could be applied to such an idea.