It does already align with acceptable accuracy on Prince, just not on Deity (or in general: the other difficulty levels). I’m talking in terms of an average game, it is fine from my side to have unusual situations, this cannot be prevented, there is no need to make mathematically precise alignments. I have no such desire.
“every other aspect of history has been thrown to the wind” – statement is a huge exaggeration in my opinion. Or at least I don’t have this impression. Certainly not “every”.
No, the design deviations are non-trivial and permeate the entire experience. It really is true that a desire to match calendar timing with historical progression is mistaken. Worse, it's flat-out incoherent, you can't make a case for history in just this context while coming from a rational framework.
IRL history's discovery pacing (and everything else) followed a causal chain of events, and those events did not begin with "empires led by a single, 6000+ year spanning entity optimizing for the empire's well-being as the top priority", nor did most begin with a single settlement and a tiny military with lots of uncontested land.
This is before we touch an population growth, logistics/supply by era, borders, actual combat, zone of control, ruler/local entity decision-making, pre-paper map-making, or a ton of other mechanics.
Complaining that the game allows/expects faster timing at high difficulties because of the misalignment of history (as opposed to other reasons) while accepting its premise is incoherent. You are necessarily trying to equate acausal outcomes with causal history. That doesn't work.
Put an entity in history leading a nation that only cares about the well-being of that nation, knows future techs and plans for them in advance, sees entire military top-down and can control them, and can micromanage how the nation's pop (which for some reason grows more slowly while having more people) and you have something that in no way resembles our history. Unless you ignore causality, it SHOULDN'T resemble history.
Arguing to ignore causality in favor of historical events is self-inconsistent and has zero credibility in any game debate. Objectively. History depended on its causes. Throw that out, and you necessarily threw out history too. You can't separate them.
TL;DR version: What this means in civ is that 500 AD computers is no more or less reasonable than any other mechanic unless you can find a non-history argument against it. This thread is lacking in coherent non-history arguments against it.