Ah, but the difference between the kakapo and kiwi is that despite its rarity, the kiwi is kept in zoos outside of New Zealand. The kakapo isn't even kept in zoos inside of New Zealand. In any case what's normal or rare in one place isn't normal or rare somewhere else - I often get the feeling that the game is heavily focussed on animals found in European zoos rather than looking elsewhere (well...European and San Diego). That's another reason why the lack of a Tasmanian devil really ground my gears; they might not be common in zoos in Europe, but down here in Oceania they're in a whole lot of zoos and extremely important to the captive breeding programme.
Oh I agree, commented multiple times about people mentioning the Emperor zoo or the pink fairy armadillo and some have been vocal about the Javan Rhino as well. Species not in zoos or only 1 country - don't think that represents the "common" zoo..
I understand that some species will get special treatment because they are iconic to a continent. So some species will always be debatable or will be added to don't leave out a region.
Going with your example of the Tasmanian Devil: only a few zoos have them in NA (saw a google result of only 7 in NA), and saw 1 result for Europe (only 6).
So let's say 10 zoos in Europe and NA have them - that's pretty rare. I think Oceania is even unique in mostly keeping their own species in their own zoos - which is understandable .
My overall impression is that African species are extremely well represented in most zoos - so that's pretty accurate with PZ. (and still "missing" some iconic and common species)
Main reason why I think 1 European pack is enough to represent Europe in PZ.