Repost, but modified from suggestions:
In order to discern the remaining Civs, we can start by looking how Civ V empires have been carried forward in one of 4 ways:
1: Direct Representation
- Vanilla: America, England, Egypt, Japan, China, Aztecs, France, Brazil, Germany, Spain, India, Greece, Arabia
- DLC: Poland, Persia, Indonesia
- Rise & Fall: Korea, Netherlands, Mongolia, Zulu
- Gathering Storm: Inca, Sweden, Ottomans
- New Frontier: Maya, Ethiopia, Byzantium, Babylon
2: Slant Representation (similar or historically close civilization substitutes)
- Vanilla: Scythia for Huns, Norway for Denmark, Sumeria for Assyria
- DLC: Khmer for Siam
- Gathering Storm: Hungary for Austria, Mäori for Polynesia, Mali for Songhai, Phoenicia for Carthage
- New Frontier: Gaul for Celts
3: City-State Representation: Fez for Morocco, Lisbon for Portugal, Venice...for Venice
4: Split Representation:
- Macedon from Greece
- Nubia from Egypt
- Scotland from England or Celts
So this comes to the last slant representations for North America: Haudenosaunee (Iroquois) and Shoshone, it could be a tossup as to who the Cree slant represent, giving hope to the final DLC being SW North America for the Shoshone. Or crushing all hope and making Portugal the last DLC and replacing Lisbon City-State with one representing either the Haudenosaunee or the Shoshone (depending on what Firaxis considers the slant representation of the Cree.)
The new Civs are from previously unaccounted for geographic “diasporas” (using the term loosely) and do not particularly follow a pattern other than being between 1-2.
- Vanilla: Kongo
- DLC: Australia
- Rise & Fall: Georgia, Mapuche
- Gathering Storm: Canada
- New Frontier: Gran Colombia, Vietnam
This leads me to assume that there will be no more new Civ regions as of Babylon leaks.