We had a discussion on this in this thread where we listed most of the ideas you mention:
Australia Zoo News 2022 [Australia Zoo]
I would identify a Sumatran elephant bull, on display exhibits for the Cheetah and a diversification of species on the Savannah as priorities; followed by a great ape species accommodated on Bindi’s Island as was the original intention and an overall decrease in gimmicks and commercialisation.
Exotic Mammal species Australia Zoo could easily source:
In that thread, I also posted this list of exotic mammal species Australia Zoo could easily source within the country (most of which are suitable for their climate):
Przewalski's horse
Black rhinoceros
Dromedary camel
Rusa
Red deer
Fallow deer
Hog deer
Banteng
Water buffalo
American bison
Barbary sheep
Indian antelope
Eland
Nyala
Common waterbuck
Addax
Scimitar-horned oryx
Black and white ruffed lemur
Golden lion tamarin
Emperor tamarin
Cotton top tamarin
Common marmoset
Pygmy marmoset
Bolivian squirrel monkey
Black-capped capuchin
Black-handed spider monkey
Hamadryas baboon
Siamang
Sumatran orangutan
Common chimpanzee
Western lowland gorilla
African lion
Snow leopard
Sri Lankan leopard
Caracal
Serval
African wild dog
Maned wolf
Fennec fox
Spotted hyena
South African created porcupine
Capybara
I will tag some of our other Australasian users who may also have ideas to add:
@Zorro,
@Matt_C,
@steveroberts,
@Jambo,
@WhistlingKite24,
@akasha,
@Abbey,
@Swanson02,
@Patrick Keegan,
@marmolady