>>543241372
cont.
All in all, I'd say LA doesn't quite advance the timeline. It does a little bit, but in a weird way (why is everyone reacting to guns if there's no guns). LA is mostly advancing the rear end of the time span that each era covers. It's filtering out the ancient stuff, the wide variety of mythological and fantastical creatures and magic.
So, to summarize:
EA: literal stone age, but more generally pre-Bronze Age Collapse to mid Roman Empire, roughly 5.000 b.C. to 100 a.C. Without outliers, rather 700 b.C. to 100 a.C. We can generally call it Bronze Age but it also steps deeply into the Iron Age. Ancient and Classical eras would maybe be a better descriptor, although it still won't cover the outliers.
MA: Still pre-Bronze Collapse to late Middle ages / early Renaissance. Trying to average things out, I'd say dark ages to early Middle Ages, but that's like saying that if I eat two chickens and you eat none, both of us ate one chicken on average. Technically correct, but we got too many outliers for the average to be useful at all.
LA: MA but less fantastical stuff and more homogeneized. Here we could try to say that average around late Middle Age.