Australia is indeed overdue for a visit (season 18). Too bad Melbourne during last season's filming turned out to be Israel and not us
But they're probably headed to Africa or Europe as per usual.
You can add New Zealand as well (last visit was TAR22). Yeah it sad to see Melbourne not featured on TAR28 but in retrospect I'm glad it didn't waste on the meh-****ty TAR28 cast.
Fun Fact of Aus/NZ visit: Every Aus/NZ visit since TAR13 was featured on the
Westward route while the last Aus/NZ visit featured on the
Eastward route was TAR9.
Europe would be my bet for their next destination after South America tho.