I was never a huge fan of the older master plan, to be honest. Islands is a pretty awesome concept and I hope it comes back, but the various North America areas while individually charming felt very jumbled and unfocused as part of a final product by dividing the animals over a larger area w and it was clear Milwaukee continuing polar bears was not feasible at all. The Jungle felt like it was pencilied in as a placeholder for when they got around to it.
I'd love to see Islands back, I'd love to see wolf and moose return in a future North America renovation, sea otters would be neat, and we definitely need some Australia representation back, but I think completing Adventure Africa and renovating Small Mammals are already really rewarding projects. I would honestly suggest they renovate primates after that's done with, as it is much more glaring and antiquated than the reptile and aquatics building, which could use work but isn't as noticeably out of date to the average guest.
There's also the bear dens, which really need to go, of course, but the elk and reindeer exhibits are solid. Adding new bear and wolf habitats, and if possible moose, to the North America area would be a winner.
As much as the Africa/Asia/Big Cats/South America section could use improvement, it will be colossally expensive to interact with the inner big cat sections, construction will threaten the core of the collection, and the changes to Adventure Africa have just happened, so I would recommend they take a break from that area and come back later on. I think they should consider finding space for the remaining Asia or South America animals elsewhere in the facility so they can narrow the focus of renovations.