Aside from the trailer? Alright, how about the description?
Spoiler Our fate does not hang in the balance because Hermaeous Mora wins it either way.
The fate of Solstheim doesn't hang in the balance because nothing really happens outside of Apocrypha and Miraak was never going to win and achieve his goal anyway.
And our "deadliest adversary"? That's a joke. We only have one fight with the guy and Hermaeous Mora ends up killing him. Hermaeous Mora was the antagonist of the DLC, not Miraak (who was really just his puppet the whole time).
I spoke with MerchantMudCrab on this matter in another thread, and he too essentially said HM was the real evil entity here. He personally enjoyed this twist, I on the other hand didn't., primarily because we were mis-informed about what this DLC would entail. I can't agree with you that this is 'over-hyping.' Hyping something is shamelessly promoting things through constant developer feeds, advertisemants, etc. Star Wars: The Old Republic or Hitman: Absolution are both shining examples of over-hyping. There's a pretty big difference between misinformed and hyping. Nonetheless, you're still right, the trailer and the description were misinforming to say the least.
As far as Miraak goes, he's a lost opportunity for what could have been some incredible writing, lore wise. We have here the first Dragonborn, and...that's it. We know very little about how he was dethroned, besides the fact that one dragon priest.... or several, or maybe 1 dragon priest and several dragons, or perhaps one dragon and three dragon priests...see what I mean? And then we're all wondering how he's the first Dragonborn, and even that itself is touched upon by a side-narrative. We rarely see or hear anything relating to the big man himself, aside from when he A) Says your feats are petty and sends you back to Solstheim

Steals your Dragon Souls and C) The Final Battle at Apocrypha.
Meanwhile, HM is just soaking in the rays with his overly sinister voice, driving the Dragonborn harder than a Dunmer with 15 slaves. He sends us on some wild [censored] goose chase, makes us stand by and watch him kill Storn in a manner that would cause Vlad the Impaler to punch his fist out from his grave and give a thumbs up. And then he steals the spotlight and kills the antagonist right before our eyes. I'd be more understanding if this DLC was called 'Apocrypha,' or 'Tentacle mutant fetish part deux,' but it's [censored] called 'Dragonborn.'