From FIFA
http://resources.fifa.com/mm/document/affederation/generic/02/78/29/07/fifastatutsweben_neutral.pdf
If a player has more than one nationality, or if a player acquires a new nationality (this is Roly), or if a player is eligible to play for several representative teams due to nationality, he may, only once, request to change the association for which he is eligible to play international matches to the association of another country of which he holds nationality, subject to the following conditions:
a) He has not played a match (either in full or in part) in an official competition at “A” international level for his current association (he has played for the Dutch in U17 WCQs) , and at the time of his first full or partial appearance in an international match in an official competition for his current association, he already had the nationality of the representative team for which he wishes to play (He was not eligible for NZ at the time of those games).
Thus he cannot play for the All Whites. He can play for Curaçao because he was already eligible via this parent's birth.