I'm thinking Mogo is the best option for a third facility. Adelaide are still years away from building a Sri Lankan Leopard enclosure, and Melbourne's stance on the situation is unclear. Melbourne could plan to import Sri Lankan Leopards as part of a replacement for their Elephants; but this all depends on whether they're wanting to fully replace the entirety of the elephant complex or not.
It's exciting to see a new species becoming established within our region.
I imagine Mogo's facility will be quite small, so I imagine them taking on a single leopard; or possibly the two brothers at Canberra with the view of transferring one to Adelaide when their exhibit is constructed. Similarly, I could see Melbourne Zoo becoming a non breeding holder with a sibling pair held as ambassador animals.
I hope this interest spreads to New Zealand. They'd be exciting additions to Auckland and Hamilton Zoo. Wellington Zoo have no interest in acquiring them given their efforts are going towards importing Snow leopard in the next year and that their climate isn't ideal.