It's where more than one species(often predator and prey) are exhibited in such a manner that it appears they share the same space and are often separated by dry moats hidden from the public. This take was pioneered by Carl Hagenbeck.
Sounds similar to the Islands exhibit at Louisville which also rotates tigers, orangutans, and gibbons, with babirusa and tapir instead of bears.
Rotational exhibits can be effective at providing additional stimulation to their inhabitants and make for a more dynamic guest experience, although their effectiveness varies from exhibit to exhibit. The key to a successful rotational exhibit is to make sure the species being rotated all have similar husbandry needs. Some of the most notable exhibit complexes centered around rotation all have a focus on a specific group of species: Elephant Passage at Denver, Primate Canopy Trails at Saint Louis, Big Cat Falls at Philadelphia, etc. Exhibits like Louisville's Islands and Point Defiance's Asian Forest Sanctuary suffer from the fact that the species being rotated are all vastly different and not every enclosure is best-suited for each of them. I'm not all that familiar with Perth, although after reading the page linked above I worry that its future exhibit will have similar issues.
Fully flighted birds like vultures, flamingos, pelicans, or cranes would look neat with savanna animals. Though I could see the costs being prohibitive.
