Khajiit lore was great. But now we've moved on to pretending to care about Nord lore, while really caring about vampire lore. For some stupid reason.
Don't get me wrong, the Gray Host stuff is really cool and I'm glad someone dug that out of the archives to give it another look. And the implications of what the Host are doing is...interesting, to say the least. But at the same time, there's only so many variations we can have on vampires and I honestly cannot take a gothic castle in Blackreach even the tiniest bit seriously. Did the landscaping devs do a wonderful job on it? Absolutely, they always kill it and I bet it was a blast to work on. But fuck me, it's so fucking stupid conceptually.
Even worse, the ending of the DLC suggests two things. 1, they're going to the Reach with the Q4 DLC. And two, it's still going to be focused on vampires. This means less time spent on the Reachmen, which means almost invariably more "herp-a-derp Reachmen are evil don't overthink it" writing. There's literally one non-evil Reachman in the entire game, and that's done entirely to emotionally manipulate you when faced with the choice of killing him or a Nord soldier to advance the storyline.
Perhaps I'll be wrong. But given the importance of the Reach to the overall plotline of ESO (their conquest of Cyrodiil set many of the chain of events into motion, not to mention they are primary enemies in at least four major zones and two DLC dungeons), they really deserve an entire chapter devoted to them, at the very least to give them the chance to tell their side of the story. But they won't get one, if Q4 is the Reach and not Whiterun/The Pale/Winterhold.