The term we should be using is "locally adapted". Too much xenophobia and black-and-white viewpoints when we start using terms like "native".
Living in South Devon we see an awful lot of Buckfast-derived stocks, and to be honest the local, indigenous, native, mongrel, call-it-what-you-will bee is more than a bit Buckfasty. I suppose that was the intention of the Buckfast strain - something suited to the beekeeper and the local climate/forage. Is it a surprise that elements have survived in the wild? No. They are the locally-adapted elements.
People seem to think Buckfast is some strange little place on Mars, totally unrelated to the British climate. Perhaps they've forgotten that it is a place as well as a brand. Actually, Buckfast is a small damp village under the southern reaches of Dartmoor, and Br. Adam's bees were kept up on the moors, principally for a heather crop. It often puzzles me when I'm up there peering through the fog and drizzle and bracing myself against the wind that beekeepers from the wetter, windier areas of the country discount Buckfast out of hand as unsuited to their climate.
Similarly these "NZ bees" are in fact north European Carnicas raised in NZ for reasons of climate and timing. The selection and breeding was done in Germany, NZ is just acting as an incubator and mating station. It may suit some to keep referring to them as NZ since it makes them sound more foreign; others may not be aware of their true origin.
One day somebody at BIBBA will have a light-bulb moment and send Amm breeding stock across to somewhere like NZ, so that suddenly Amm queens can be cheap, plentiful, and most importantly available in quantity at the right time of the year in the UK. If that ever does happen, I shall be sat on the sidelines (as a member) with a giant bucket of popcorn, watching the hand-wringing, soul-searching and semantic wrangling as they try to work out whether these imports are acceptable "native" Amm or some Antipodean aberration. "The morphometry says 'yes', but the heart says 'no'. We want to promote Amm, but we don't want to promote
that Amm." Priceless
See it's not black and white; no strain is wholly good or wholly bad. There's a lot of emotional capital tied up in wanting the "native" bee to exist, and for it to be the best. Just because Amm has been here a long time doesn't mean that it will be the best, rather it means that it won't be the worst. Just because imported genes change the balance of the gene pool, it doesn't mean it always changes for the worse.