A couple of little comments. The fact that teams aren't headed to a particular airline hub as the destination for the next leg does not mean that hub isn't being used as a first or second connection point to the real destination.
Second, there may be some merit to having an extended pit stop, especially if the destination involves multiple flight segments and a long total elapsed travel time. That would also support sighting Phil or production (Phil, for a lead time to the next leg location; production often leap frogs to the leg or country following that.)
Third, the sequester location is not necessarily going to be determined by the location of these first legs but rather by the final destination city that is being planned for this race, and being able to have a direct route to get the eliminated teams there.
As to possible locations of the next leg, there are a few aren't there? I would think a location adjacent to the Indian Ocean would be likely candidates at this point whether that be in south Asia, southeast Asia, the Arabian peninsula (i.e., UAE) or eastern Africa. I suspect we're not quite ready for Europe at this point, so I wouldn't rule out central Asia (one of the "stans," or the republic of Georgia, for example. In other words, I think a new country or a nation not visited recently are the prime suspects.