Just to be clear, the post above is referring to Sumatran tigers at Adelaide Zoo (Adelaide Zoo doesn’t have Sri Lankan leopard; nor are they planning to acquire them). Five zoos hold Sri Lankan leopard: National Zoo and Aquarium, Darling Downs Zoo, Mogo Wildlife Park, Tasmania Zoo and Zambi Wildlife Retreat.
Three Sumatran tigers are being sent to the US:
1.0 Penmanah (2019) Taronga Zoo
0.1 Mawar (2019) Taronga Zoo
1.0 Ketambe (2022) Adelaide Zoo
With regards to Melbourne Zoo, the next birth may be Snow leopards if their pair receive another breeding recommendation. This will depend on regional demand, which currently isn’t there.
Otherwise, Melbourne Zoo has two 15 year old Sumatran tigers, which will likely pass on in the next five years or so. Following their deaths, there’ll be the opportunity for Melbourne Zoo to assess their future with the species - which I hope could involve importing a breeding pair from overseas (unconfirmed/speculation on my part).