Well, there is some interesting confirmations here from Black Dice Society and other places
1.) Nepenthe is a greatsword who seeks Justice(TM). Isolde is an eladrin who seeks it. The sword drives her into fits of rage when pursuing it. This is a subtle change from 2e's Isode.
2.) Azalin is NOT the Darklord of Darkon anymore. Which again fits his role as a meddler and "King without a Kingdom"
3.) Tepest got a single hag darklord rather than the trio
4.) Jandar Sunstar is a part of the setting. I don't know how much tie he stil to the Morninglord religion now...
5.) Other Groups seems like a good place for the Church of Ezra
6.) Bodytaker plants are Doppelganger plants from 2e
7.) The Caller is the Gentleman Caller who factors into Isode and Gabrielle's stories.
Seems they crammed a lot into it, though I'm disappointed many classic domains got the "less than a page" treatment in Other Domains section...
Edit: Tovag is still a domain; looks like Kas got left when Vecna left Ravenloft...