I had been wondering why there doesn't seem to be any new countries yet for season 18 and after seeing the preview, with such an emphasis on "unfinished business", it's possible they're having the teams return to "the scene of the crime", go back to the countries where they stumbled in the first place.
Kynt and Vyxsin = India
Jaime and Cara, Kisha and Jen = China
However with this theory they should've returned to Cambodia for Zev and Justin, but I'm just thinking out loud anyway.