gzt: This sounds a little unusual to me. Are you in an area where there are a high number of people with covid isolating? Do the pamphlets and fridge magnets have any 'authorised by' info? Can you post some pictures? I'm thinking this is a local dhb or iwi initiative of some kind.
Nope. It's part of the summer campaign, also radio advertising. a link to back this up...
https://covid19.govt.nz/prepare-and-stay-safe/keep-up-healthy-habits/stay-safe-this-summer/
2nd section.
Incl a pdf outlining supplies if you get stuck and need to stay in place
Basically it's the transtasman warnings pre delta. Now domestic thanks in part to the new stay at home when positive plan.