There are several discussions about how many civs we can get, and some propose like 20-30, but is tecnically imposible, look at this (From the game files):
10267 “Full Random”
10268 “Mirror”
10270 “Random”
10271 “Britons”
10272 “Franks”
10273 “Goths”
10274 “Teutons”
10275 “Japanese”
10276 “Chinese”
10277 “Byzantines”
10278 “Persians”
10279 “Saracens”
10280 “Turks”
10281 “Vikings”
10282 “Mongols”
10283 “Celts”
10284 “Spanish”
10285 “Aztecs”
10286 “Mayans”
10287 “Huns”
10288 “Koreans”
10289 “Italians”
10290 “Indians”
10291 “Incas”
10292 “Magyars”
10293 “Slavs”
10294 “Portuguese”
10295 “Ethiopians”
10296 “Malians”
10297 “Berbers”
10298 “Khmer”
10299 “Malay”
10300 “Burmese”
10301 “Vietnamese”
10302 “Bulgarians”
10303 “Tatars”
10304 “Cumans”
10305 “Lithuanians”
10306 “Burgundians”
10307 “Sicilians”
Now look the available civ spaces:
10308 “ReservedCivG”
10309 “ReservedCivH”
10310 “ReservedCivI”
10311 “ReservedCivJ”
10312 “ReservedCivK”
10313 “ReservedCivL”
10314 “ReservedCivM”
10315 “ReservedCivN”
10316 “ReservedCivO”
10317 “ReservedCivP”
10318 “ReservedCivQ”
There are only 11 available for new civs, so if we still get new civs via DLC, it will most likely be by 2 each one, and regarding the election, it should be of unexplored areas, empires and Kingdoms, NOT minor cultures or kingdoms that are like 100% covered by existing civs (cough…cough… Burgundians inclusion) or the request of dividing Slavs or Indians by like 7 factions as some propose here (just 2 more Indian civs are enough).