Sorry for the month late. I bring my stone to the building.
It has actually been announced that this year's Q4 DLC will be The Reach. This will be centralized on the Reachmens, Markarth and his despot. Without forgetting Rada al-Saran.
When Western Skyrim was announced, I was surprised at the absence of Falkreath and Whiterun. We learn however that Whiterun is now part of the eastern kingdom of Skyrim. For Falkreath on the other hand, I think either the same option as Whiterun or Colovian Estates option.
The plot in The Reach could take us to the imperials next year. Because of the old cooperation between Markarth's despot, Mannimarco and House Tharn.
But an imperial year will not be divided into Nibenay (Chapter) and Colovia (DLC) (or vice versa). Colovian Estates is just great for a Chapter. With Skingrad, Sutch and Sarchal. Maybe Epervine in DLC but that would surprise me a lot.
For the Nibenay, we will have Bravil, Ato and Mir Corrup then Leyawiin in DLC (due to its isolation further south). Leyawiin and Gideon could also be together.
The rest of Skyrim will come back once we make a detour through Cyrodiil, Martelfell, Telvanni lands and Black Marsh.
These will be territories belonging to the eastern kingdom: the map could be called Eastern Skyrim. Which would include each of the remaining châtelleries + Solstheim for the DLC.
Like Corinth-Torval, maybe Eastern Skyrim will have its share of intrigue excluding dragons or vampires.