Oh, this is just the final act of the 2.1 - 2.5 story arc, that's why it's all cutscenes with full voice acting. A lot happens in this so don't spoil yourself too much.

But starting with 2.2 there's a lot more voice acting in general, it isn't over 50%, but way more than in the base game. And with Heavensward it's at least 50% voiced. That one is kinda odd though, there isn't a lot of voice acting in the 1st act, but then it's nothing but long voice acted scenes one after the other. Kinda like you see here, it just starts earlier in the 2nd act.