If TES VI lands in Hammerfell the writers will not be starting from scratch. The Pocket Guide to the Empire, 1st Edition already laid out the broad strokes in 1998, and later books have only added detail rather than contradiction.
The short version from the sources:
- Yokuda sank in the Merethic Era after a combination of natural cataclysm and internal strife (Pocket Guide, PGE1).
- The surviving Redguards arrived in Hammerfell in 1E 808 and spent the next several centuries pushing the borders of what became Sentinel, Hegathe, and the Alik'r holdings.
- The Ansei and their Shehai technique appear in The Book of Circles and in scattered references by Yaghoub and Derik Hallin, though the art is described as already in decline by the Second Era.
- The Forebears and Crowns split is political, not religious, and dates to the arrival itself rather than any later event.
What the books actually give us is a culture shaped by loss of homeland and repeated wars with the left-handers, then with the Empire, then with the Dominion. The lore does not promise a single unbroken tradition. It shows repeated adaptation under pressure.
The 2920 and 2E-era references add that the Yokudan language and certain martial rites survived in isolated monasteries even after the loss of the art of the Shehai. If the writers want a through-line for a Fourth Era story, those monasteries are already on the page. The same goes for the city-states that maintained uneasy truces with the Crowns while still paying lip service to the Empire after the Warp in the West.
Nothing here requires new invention. The gaps are the usual ones: exact dates for the final sinking of Yokuda, the full roster of which Ansei survived the journey, and whether any remnant of the old pantheon still operates in the deep desert. Those are the same sorts of gaps the series has always left for later games to fill or ignore.
The conversation doesn't have to wait for an announcement. The texts are already here.
https://elderscrollsforum.org/vi/p/1-tes6-everything-we-know
https://elderscrollsforum.org/vi/d/101-introduce-yourself
Which single book or in-game text do you treat as the strongest anchor for any Hammerfell story, and why?