Disney doesn't own the Atlantis mythos, they used it specifically because it's public domain, like Snow White, Aladin, etc. Only Tarzan has been a project they had to get the rights to do from the author's family.
It seems to me like Indy would have to be underwater a lot for Atlantis to work though. As for Stonehenge or Easter Island, wouldn't that be a REALLY short movie? I mean, it'd just be Indy shown getting on a plane, then a map with a red trail leading to England and then the South Pacific, and finally a shot of Indy getting off the plane. Perhaps the Stonehenge one might take Indy all the way to the car rental place as well.