It is very clearly not based on Australia or anywhere else other than New Zealand and that has been confirmed. If we got an Australian world, that would look completely different and I would expect to see Aboriginal and Torres Strait Islander peoples.
As for English speakers not understanding the places if they are in te reo Maori, how many English speakers understand the names of the places in Sulani - Mua Pel'am, Ohan'ali Town, Lani St. Taz? What about Mt Komorebi - Wakaba, Senbamachi, Yukimatsu? These are the names given to Polynesian and Japanese inspired Sims 4 worlds. That's all I'm asking for in a New Zealand inspired world.
Honestly, this has as much to do with representing New Zealand accurately as it does being an erased indigenous person. Place names in New Zealand are predominantly Maori place names. Pretending that is not the case not only white washes the game, but makes the game boring and less fun to explore.