Cabinet papers show ministers approved plans a year ago to reunite families split by the border but later said it was not necessary.
Figures within the briefings show about 14,000 partners and children not covered by other border exemptions were among those waiting to come in last July.
"I propose to introduce a border exception to enable partners and dependents of all eligible onshore temporary work visa holders to enter New Zealand," said then immigration minister Kris Faafoi in his briefing to Cabinet.
"While this is a potentially large group, this approach will enable those who have been caught by the border closure, the comfort of knowing that they can be reunited."
First priority would have gone to those issued relationship-based visas before the border closed (about 1600 people), those whose relationship-based visa applications were paused due to the border closure (4000), followed by employer-sponsored visaholders (3500) and all other temporary visa holders with partners and dependents (5000).
The documents, published on Friday, show Cabinet agreed to the change in border settings in principle on 12 July, subject to timing and phasing of the border exceptions. It delayed the decision for a month because of managed isolation (MIQ), which was accommodating more travellers after the suspension of the trans-Tasman travel bubble.
"In light of the rapidly evolving situation with Australia, officials recommend decisions on timing are deferred until early September," said the next briefing on 19 August. "This will allow time for MIQ to move past the current 'incident management' response, and gain clarity on the likely impact of the suspension on MIQ demand."
On 30 September, the government announced publicly it would offer 'one-off' residence to up to 165,000 migrants in 110,000 applications, which has since risen to 214,000 people.
Cabinet met the same day and took the decision that "in light of the decision on one-off residence, the family reunification border exception is no longer needed, as many workers will be able to bring their eligible partners and dependents to New Zealand as part of their residence application".
'Still separated'
Immigration adviser Katy Armstrong who has campaigned for changes, said she was "gobsmacked" by the news that Cabinet signed off on reuniting split families.
"You realise that they were actually contemplating going 'right everybody can come'. It would have been brilliant, it would have been the absolute solution to all our woes.
"It's almost like a dagger to your heart, we were so nearly there but we never knew it. It's sort of vindicating on the one hand. But it feels almost worse to know we were so nearly there and then they retracted it all."
The one-off residence visa - known as RV21 - was supposed to solve the issue of split families, but there had been further delays and they had been given no priority, she said.
Only 40 percent have been finalised overall and the promised 12-month timeframe for most to be completed has been extended until the middle of next year.
"The minister [Kris Faafoi] kept standing up and saying this is going to reunite more families. And we were going 'no, it's not and it's not going to do it quickly enough.' And we were advocating for priority in the RV21 to be given to split families if that was what the government was going to pin everything on. And then the minister said it's not going to take 12 months, it's going to take 18.
"The worst [cases] are the ones who put all their store by the RV21 precisely because the government was saying outwardly it is going to be your salvation. And we've got families who went down that route and they're still separated."
In many residence cases split families have taken longer than those who are together in New Zealand, or people with no families, she said. Applications became 'stuck' in the system often for no apparent reason.
The timing of the Cabinet papers' release - they were published on Friday - pointed to a continuing lack of transparency, she added.
"Why did they sit on that? Now that's over a year ago, that's incredible really and it feels to me as though they've timed it. t's a way of releasing that information, probably making less noise, they just slip it out. And then we got to the February border opening, and we said please now we don't have MIQ let the families in and they still didn't let them in. Why?"