Given the logistical challenges of aligning the qualifying processes of two different confederations they may decide to simply retain a two-legged Asia/Oceania play-off. That would still satisfy Asia and Oceania's desire for a slightly easier qualifying path, but not our own desire for more games. The other Oceania nations might consider that rolling the dice in a two-legged play-off would give them a better chance (and maybe cost less) than competing in a longer round of Asian qualifying (if they make it that far) so might push for that option.
Oceania are doing the negotiating. Not NZF. They would have already taken into account those issues when you consider that OFC is predominantly an 'island run' confederation. NZF get fuck all say in any matters. Invariably, NZ are the qualifiers in 90% of the cases so we are the main benefactors (or alternatively, punished) in any decision made but OFC with the 10 other island nations will already have this thought of.
Besides, as someone said, isn't the TV rights sooooo lucrative that it pays for itself? The island nations, if they got there, would have nothing to worry about...