I am judgemental of Bronze Age morals, but that's because I live in the modern age and we've luckily figured a lot of this stuff out. I also don't have to pretend that these stories are timeless and by extension make all sorts of apologies for wicked acts, some commanded by God, in the OT.
We thankfully live in an age where child murder and genocide are not needed to sort out our problems, and our military thankfully takes into account collateral damage and liberates the woman and children of oppressed regimes, instead of slaughtering them.
The three-age system is a quasi-modern notion with no real scientific or even archaelological basis. It was concocted by Christian Jürgensen Thomsen (“Christian” is his first name, FTR) who based it on notions from Greek and Roman philosophers, Hesiod and Lucretius particularly. Certainly the Bible indicates antediluvian use of iron, attributed to Tubalcain; and King Og of Bashan was said to have had a bed of iron. Egypt is euphemistically referred to as an “iron furnace” in Deuteronomy 4:20.
BTW, the iron age is conceived as the point in human history when writing became most prevalent, whether with pictographic, logographic, syllabic or alphabetic writing systems. So perhaps you mean “iron age morals”?
I really see no difference between the morals of today and back then—or specifically, the lack of morals, because things are getting worse, not better (I’m aware that the humanist view is the opposite, but the evidence does not bear that out). Genocide is far more prevalent today than back then, and slavery is more prevalent worldwide than at any time in human history.
No, not “historical fact”. Unless the historians have time machines? It’s historical conjecture, if not outright revisionism.