The FH journey so far has been America>Europe>Oceania>Europe>America.
They finally closed the loop going back to where it all started. Right now that means so far 2 FH have been located in America, 2 in Europe, and since Oceania has already been essentially done with Australia (I don't think they will go again for New Zealand for example, plenty of really new places to explore first) we are still missing the entirety of Asia and Africa, to start with. So if they start another loop, it will not follow the logic of the first since that would mean going back to Europe, leaving those continents aside yet again.
So, long story short, my probable guesses for FH6 would be:
-Japan (The obvious choice at this point, but if they eventually do Asia, unless they want to be creative and feature Korea, Malaysia, India, or maybe something more original for example, this is it)
-Madagascar/Réunion (Or any other place in Africa, I wouldn't be surprised if they decide to do so to start here, The Grand Tour already shown why)
-Canary Islands (Again, I don't think they will go back to Europe any time soon after FH2 and FH4, but when the time comes, would be a great idea I think. Ibiza has already been done for TDU2, and would be a good creative choice. If not, well...many, many other places or even countries they can compress into a FH map, so who knows)
-Every single island in central/south America, plenty of choices...unless they go for a whole mainland country again.
It's hard to tell since they don't go for actual 1:1 replicas of the real place, like TDU. That would limit things up to a certain point, since that involves going to an island to have natural and easy to do game limits (in fact, the upcoming new TD could use any of the previous ideas nicely because of this reason) but since PG can squeeze any country into a custom map, everything is possible, unless they take the TD route. The easier question would be what continent, and again, Asia or Africa would be the first choices for sure.
