I like the interesting review of, shall we say, unconventional approach to pre-1773 American history.
My fave bit in the video was about those huge Native American copper mines... and the distinct absence of such an immense volume of copper artifacts in North America.
(A couple of copper arrow points? Really? So… where did all that copper go?)
I vote for Greco-Roman cross-Atlantic trade, myself.
And for Traveller?
Officially, the First Imperium, the Ziru Sirka, kicked in at the same time the Western Roman Empire fell. But the Vilani have been starfarers for 5000 years before this date, in their (at the time) small pocket of space.
The Vilani, being both bureaucratic/conformist and eager for profit (in the corporate sense, not the free-wheeling entrepreneurial style), could have easily traded with interesting and mysterious cultures that have long been lost in time.
Some of those cultures may have even independently found jump drives before being absorbed into the Ziru Sirka (“…like the Geonee…”) or simply exterminated (“the Vegans had a really close call here, but managed to survive their encounter with the Imperial Vilani…”)
But there are those cultures which escaped both fates… and, if they didn’t fit in their assigned Vilani mental boxes, they were no doubt filed and forgotten. Or… the corners simply chopped off in the books and the records, or the annoying details simply left out or just blatantly lied about: “the nail that sticks up will be hammered down”.
But, there will be tell-tales and inconsistencies in the records, hints that will be worth investigating by the curious and the daring.
I can imagine curious researchers uncovering the carefully kept records (“…untouched for the last 2,800 years…”), and decided to hire a band of adventurers to get at the bottom of it… write a revolutionary paper.. and, maybe, grab a few valuable artifacts for sale for nice, fat profits back home…
Traveller has a lot of untouched background out there. Why not flesh it out, increasing interest and opportunity?