I wonder what new species could be brought in for Tropic World once the additions are complete. 'Tragic World' is already very sparse, and the new exhibits will leave the indoor area pretty much completely empty.
I think the zoo will bring 3-10 new species, including a couple new primates for the complex. Brookfield has a good track record in the past 5 years of bringing in new species, including exciting and rare ones, and ones of conservation concern, so I think a little optimism is warranted.
As I have seen mentioned, I think Mandrills are a good candidate. They are big, colorful, and capable of filling some of the indoor space quite nicely.
Wolf's Guenon, Diana Monkey, and DeBrazza's Monkey are also likely African monkeys that are present in AZA institutions. Lesser Spot-nosed and Stuhlmann’s Blue Monkey are reach species, and I'm not so sure how their populations are doing, but they are also present in some numbers at AZA facilities. Baboon species probably would not do well in a mix, but I could see one in the current gorilla exhibit if a Mandrill doesn't go in there.