@Paisley_Trees , history student and civ enthusiast, and one of her colleagues, are discussing the civ switching in a new video.
They discuss in depth how culture involves, that cultures do not vanish, but that we still have aspects from past civilizations with us. This includes the topic from one of the controversial threads/reddit topics, of colonized civilizations potentially being replaced by colonizing civilizations (to note: This has not been shown anywhere, and is purely speculative), which indeed would be inappropriate.
They discuss the historical appropriate choices, and what the logic behind is. They conclude that there is obviously some compromise, between gameplay choices and historical options, and that people need to be more relaxed about these details. They suggest that instead of "historical choice" Firaxis should use "influenced by" or "sphere of influence", to avoid the direct historical tie. Or even taken from @PotatoMcWhiskey "the closest thing we got".
The video is pretty nice. If you're interested in the civ-switching mechanic (and whom are we kidding... everyone here is), then have a look at it.