I don't know specific details regarding what is still planned. I know for a fact okapi are no longer going to be an addition, not sure why. If it was up to me to assume I'd say a gorilla expansion is possible alongside maybe a new habitat for the lemurs but that is just guess work at this point in time. If he has the time, I've kindly asked Steve to seek an answer on this when he visits next week so we should wish him luck on this!
Australia doesn’t have a Giraffe/Okapi IRA and this will still be a number of years off. Combined with the fact there’s a lack of surplus Okapi in North American and European zoos (especially cows) and it’s a bit of a non-starter.
Auckland Zoo were reportedly considering an African forest precinct a couple of years ago, which has since been rejected in favour of expanding their rhino facilities. Had Auckland Zoo come on board with the Okapi, they could have quarantined a pair in New Zealand, prior to sending them on to Australia (Australia can import from New Zealand). This is how Dubbo received their female Eastern bongo.