A law expert says the government's move to allow unvaccinated New Zealanders to skip MIQ show the rules are changing with the country's evolving Omicron outbreak.
The government quietly changed the rules on Friday but did not announce it.
On the MIQ website, there was a statement published which said "The Government has agreed that unvaccinated New Zealand citizens, and those who are eligible to travel to New Zealand do not need to enter MIQ or to self-isolate."
The change took effect from 11.59pm Friday.
"This also means that those eligible unvaccinated arrivals who entered MIQ prior to 11.59pm on Friday 18 March will be released from MIQ," the statement continued.
Minimum vaccination requirements for travel to New Zealand will apply to non-New Zealand citizens, including permanent residents, unless they have an exemption. Testing requirements also remain the same, with arrivals required to take rapid antigen tests on days 0/1 and 5/6 and report the results. If a traveller is positive for Covid-19 they will need to take a PCR test and isolate.
Waikato University Law Professor Al Gillespie said it shows flexible thinking on the government's part.
"Whenever you've got restrictions on the liberties of New Zealanders, they must be justified.
"And they've obviously gone through the work and decided that this restriction right now is no longer justifiable and they've decided to remove it.
"It's good because it shows that there's continual review."
Gillespie said he expects more changes will follow.
"There's two points here, one that the government keeps reviewing everything, which is good, that's commendable.
"But as much as things are removed if there was change in the virus or the collective need required changed again we could see them come back on, but for now it's definitely the right direction."
National Party Covid-19 spokesperson Chris Bishop said the rule change to allow unvaccinated New Zealanders to dodge MIQ brings the whole traffic light system into question.
"If you no longer have to be vaccinated to enter New Zealand, why are the unvaccinated subject to all of the rules and restrictions that they are in New Zealand right now?
"You know around getting a haircut for example, young kids participating in sport, entering cafes and restaurants and things like that. So it really does throw into stark relief the whole future of the traffic light system."
Ardern announced last week that the borders would also be open to vaccinated Australians only from 13 April.
Bishop said the government needs to publish the legal order made around the decision and clarify details.
The government has already previously announced that many Covid restrictions including vaccine passes would ease once the country was past the peak of Omicron.
Bishop said it was bizarre the change to MIQ requirements was not publicly announced.
It was announced last week that MIQ will reduce to four facilities by the end of June as the system is wound up.
MIQ will still be used in limited circumstances, by some refugees, arrivals from Afghanistan, maritime crew, and some international aircrew, the government said.