For example: at some point in human history, the idea of a false identity or alias wouldn't have even made sense

I don't know about that -- the Odyssey, for example, doesn't have any trouble with the idea of a false identity...

Technically you are correct, of course, I don't know if the concept of false identity would have made sense to a paleolithic tribe, and if it did we can always go earlier until it wouldn't. But at this stage, a LOT of contemporary concepts would disappear.

As to your game, I think you need to limit it in some way, otherwise too much stuff (from women's rights to telecommunications) qualifies.