Kakapo tend not to be kept in captivity (except rescue birds) and are especially not exported out of New Zealand. From a conservation perspective, I'd rather not see them in-game. I would be okay with the kiwi if we had a nocturnal house system implemented, purely for realism.
Personally I'd rather they tried to find a way to make peafowl (and other future pheasants or waterfowl) free-roaming. I have wondered if there's a way to make the animal work a bit like the staff do, where you can assign them to a "work zone" that they never leave. That way you can keep their food/water/enrichment contained to a specific part of the zoo and they won't wander off to starve or die of thirst. I'd like to see the Lady Amhearst's and golden pheasants added at some point if we can make them free-roaming, and the Himalayan monal would be a good one to add to complete the Himalayan exhibit (with the red pandas, snow leopards, and so on).
I agree that I'd rather the emu was added with other Australian animals. I hope that Frontier realises as well that emu can be put in walkthrough enclosures (Auckland Zoo and Wellington Zoo here in New Zealand do that and it works perfectly, and they're mixed with grey kangaroos).
I'd also like to see the American/Caribbean flamingo added. I know it will be a copy-paste animal, but the colours are just so much more vivid than on the greater flamingo.