I mean from the Humankind devs have said, the different 'cultures' making up your empire across the game IS the thesis - that any culture is actually the sum of many different cultures.
You can certainly argue that Civ 6 is attempting to bring some lesser known civs and leader into the light. You can also argue that it emphasizes a largely discredited 'great man' version of history, feeds into stereotypes of innate characteristics of peoples (Germans are productive! Koreans are scientific!), and - as the complaints from the Cree tribe emphasized - are possibly MORE damaging by forcing a lot of those 'lesser known' civs into a explicitly Western model of historical progression, conquest and colonization, and religion that they never abided by.
Eh, I think there is a bit more truth to the "great man" version of history than people give credit to. Case in point, three of the four largest religions, followed by almost 2/3 of the world population, have a pseudo-historical cult of personality at their center. The public generally is more susceptible to "great man" romanticization than I think anyone would like to believe. It's problematic, it's undesireable, but it's not wholly
inaccurate. And it's still fairly pervasive in cultural mythos as well.
Stereotyping peoples. Fine. I'll grant that one to you, although it's at least--generally--observing regional and oftentimes global contributions and achievements by specific peoples. It celebrates things in history which were unique to them. And only consequentially stereotypes them, which, on balance, might be a price worth paying depending on context and values. By contrast, I don't see a Babylon-Maya-Arabia-Timurid-Russia-Brazil hybrid having anything decisive to say about any of its constituent parts, and in fact diluting whatever cultural truths could be expressed in that format. What you see as "stereotyping" I see as focusing design, building vertically on specific cultural throughlines, and making every civ feel unique and alive as opposed to just...including the Hittites for a sixth of the game because they were a thing, right? If VI stereotypes, then Humankind is shaping up to be just as bad in a completely different way characteristic of older Civ games, if not worse because these token representations are all stripped of any real-world
gravity.
The Cree complaints were, if I recall, based a bit on overall Amerindian pacifist revisionism. The Cree were definitively an aggressively expansionist people, and it is not historically inaccurate to portray them as such. Let's also not ignore the fact that, were it not for the Cree's inclusion in Civ, Poundmaker--in many ways a symbol of Cree-Canadian relations--would never have been posthumously exonerated. I don't think taking an absolutist stance on the general propriety of appropriation/appreciation works in the context of VI which is a) doing the best it can to be respectful and overall succeeding at a level no other developer has bothered to and b) has had some social good come as a consequence of simply bringing problematic aspects of history to light.
I admit to also being somewhat disappointed in how westernized the historical progression model is, but I don't think it is nearly as bad as everyone wants to paint it. Again, every civ included so far had some period of imperialism or expansionism, so "conquest and colonization" is not historically incorrect. Similarly, many tribal religions, although not institutionalized to the same extent as other religions and often protested as being of a completely different nature, are still,
de facto, religions, complete with rituals, stories, and holy men. Sure, we can argue that not every civ has shrines
and/or temples
and/or worship buildings, but these are still thankfully very generic and inclusive ideas. So I would argue it's only the tech trees and certain districts/improvements/units where things start to really get shaky (especially Great People which are
heavily skewed toward Europe), but at the end of the day, these progressions still reasonably expressed
many of the civs on the roster, if only as a consequence of globalism. At any rate, VI is a massive improvement in terms of representation over prior installments.