The fate of Gilane
A couple times, I've floated the idea that the city of Gilane in Hammerfell could potentially get ax'd, as we've seen with cities like Sutch in Cyrodiil and Snowhawk in Skyrim. Between the cities of Taneth, Rihad and the newly-added Abah's Landing, the region is fairly crowded, and its location on the isthmus of Hew's Bane is in equal parts rife with potential in terms of design, as well as potenttially frustrating.
With Gilane's history as an Imperial stronghold in the region, with Cephorus Septim ruling as king there prior to his ascension to the Ruby Throne, and Gilane conveniently not appearing on the East Empire Company map in Skyrim, I could see Bethesda potentially setting-up Gilane being destroyed by the Aldmeri during their invasion and occupation of southern Hammerfell.
If that's the case, then that could open-up some interesting avenues for storytelling. Gilane, the city, is gone, but Gilane, the kingdom, isn't, with the royal family moving their seat to Abah's Landing, perhaps leading to a power struggle between said royal family and the city's merchant lords. Though a ruin, Gilane would still have much strategic significance, with whoever controls it also controling the land trade between Abah's Landing and the rest of Hammerfell.
There could be a questline, where the player character helps the royal family retake the ruins, with them in turn being named castellan and charged with holding and rebuilding the city. This could essentially be our settlement building mechanic, with us starting out with rebuilding the citadel, then the walls and surrounding districts. And as castellan, we could involve ourselves in the power struggle in Abah's Landing, either staying loyal to the royal family and help them regain a foothold on the mainland, or side with the merchant lords against them and perhaps even usurping them, the merchant lords being content with us calling outselves royals, so long as we allow them to continue doing business as usual.