The exhibits ageing way faster then expected, so I wouldn't be surprised if it was demolished within the next decade to make way for another enclosure for another species.
I'm of the belief that the camels are a 'temporary' replacement until a more complete decision is made on the future of the enclosure. The camels do link in nicely with the nearby Australian precinct, so I assume that's where the thinking comes from; placing them there.
I don't see elephants returning there, the enclosure is just too small imo.
Like
@Zoofan15 said, the enclosure is neatly placed on one of the only large pieces of flat land Taronga has, so it would probably fit another ungulate species. Okapi (if Taronga does end up importing them) would fit the enclosure well, or even an upgraded Pygmy Hippo complex with multiple exhibits. The barn wouldn't require much changes if this was to be the case.