Not singling you out, all the articles do it, but: Strange to call this Byzantine. The coins found are from the reign of Constantius II, who at times ruled the whole empire alone (as did his successor Julian). The idea that the East, even when administered separately, was some foreign/"Byzantine"/not-really-Roman "other" was invented much later.
Sounds like we watched the same Lex interview on Rome...
Well, probably Greek-speaking rather than Latin-speaking, right? And with that, would there also be some cultural differences?
Yes, invented much later, but the expression of a different power structure that those types of Romans felt was not present. But to our modern eyes it was. Hell, the mere fact the centre of power was in Constantinople and not Rome is proof enough that they were distinct.