Here's one for an "Eligibility Expert" ....
Player born in UK (2000)
Parents born in NZ : NO
Grandparents born in NZ : NO
Can player get NZ Citizenship / Passport before residing in NZ ?
If Yes ..Eligible ?
Anyway, regardless of that, the answer is no, he's not eligible.
Unless the only citizenship he has ever held is NZ, in which case I think he can play. But if he's previously held or still holds a second nationality, then no.
At least that's how I read articles 5 and 7 taken together in this instance.
Edit: Thought about it a bit more, I think it depends on when he got his kiwi citizenship...