These are guidelines and not absolute criteria for the granting of exemptions even your statement "not generally considered" is not an absolute and a Minister in consideration of the request using the guidelines still has discretion to give an exemption outside the guidelines. It will need to be documented however s14 Making decisions about dispensations does not require the reasons for dispensation to be documented, just any special operating conditions.
In my line of work in the NZ side we have successfully used this and made sure there was a public announcement that the Minister had considered the guidelines etc....
Regarding caretaker provisions etc. the world still moves on. Our last Minister remained Minister for several weeks even after he was no longer a member of parliament, due to not contesting the election, but remained the Minister until he handed his warrant in, right before the swearing in of the new Cabinet.
IMO this event is definitely not something to be worried about, the reality of the curfew has not changed and there is no new binding precedent established, but we probably will never know the full story, besides whether an exemption was actually requested and approved.
Oh I live near WLG and moved there, but I also knew the airport has a curfew and would expect it to stay unless there was significant consultation/need regarding change.