I carefully disagree with your opinion, based on the plausible existence of Mississippi civ. If there are at least 2 native North Americans in the launching-day list of 31 civs, I consider that it means FXS is taking care about kinda reasonable paths for in-game civs.
Anyway I'll not say the standard of reasonable of FXS is exactly same with ours though. They could consider that Han-Ming-Meiji will work reasonably...
I think Songhai could point toward this as well. However, to pose a counterpoint: just dealing with Mississippians and Shawnee being 2 of 31, if they are being "careful," how much are we expecting "careful representation" with what we have seen representing other parts of the world? Is that possible with what we have, and two Native American civs eating up very limited space?
So far, ignoring any and all possible speculation and looking solely at what we have, it's a very mixed bag.
* We have Ashoka's India and Confucius' China, which are doing just fine.
* We have Ben leading Rome and the Normans into America, which I think actually holds up pretty well if you needed to break down "America" that way, especially with Ben as a leader.
* We have Tecumseh's Shawnee which appears to be doing just great until they hit a modern wall and have nowhere sensitive to progress toward, with the obvious choice being assimilated into American imperialism.
* We have Hatshepsut leading Abbasids, which isn't as logical a path for Egypt as Ayyubids but close enough while accommodating a potential Arabian leader.
* We have Augustus leading Spain, which is stretching even further: logically tied to his reign specifically and defining the territory of "Western Roman Empire," but still not as logical a path as anything medieval Italian.
* We have Himiko, who ends up in Meiji Japan (I think she was my biggest clue of "leader paths," incidentally), may only be progressing through Majapahit, but we don't know starts in Han, Silla, or Yamatai, two of which are very, very generous stretches and not really careful at all.
* And we have poor Amina, who has apparently visited everywhere from Timbuktu to shaking hands with the Queen of Sabaea.
I wasn't able to find a roster that gave even the leaders/civs we have sensitive paths while also keeping to 30 civs and roughly a similar sense of "connection" elsewhere in the world. Maybe someone else can give it a try and we can compare, but I think expecting 30 civs
and logical continuity may just be incompatible. There's something missing in that theory, even if it's as simple as believing that they have 30 civs confirmed now and underpromised with some confidence of being able to up the number later.