Sooo... I'm already into the new DLC and have mixed feelings about it.
[SPOILERS ABOUT DLC CONTENT, BUT NOT ABOUT THE STORY]
First, I like that there are at least 16 new Shrines (I've completed 4 standard Shrines, wHich reward you with the standard Orbs, and 3 "Champion Shrines", each of it unlocked by a "challenge" consisting in defeating certain enemy, racing through rings, etc.). The Shrines are pretty good (as good as the best of the standard game) and the challenges are nice.
However, I feel that this Expansion Pass doesn't add anything new to the base game. These are all things that coud have been in th original game (in fact, I think that is where they belong) and not in a DLC that is supposed to add something new (gameplay wise) to the existing experience. There are new dialogues, new items, new cutscenes about the deceased champions, nice Shrines (at least 16) and challenges (at least 12, 3 per champion, and at least 4 more if you count the requirements to unlock the standard shrines), etc., but most of the unexplored possibilities that were in the game, and that I expected (like rebuilding Hyrule Castle Town like we did with Tarry Town, or being allowed to dive in order to explore the depths of Hyrule water bodies, or having more minigames, since the ones in the base game are very limited) aren't there. Neither new enemies or bosses (in fact, SPOILER, except for the new divine beast, which I pressume has it's own new boss, you just revisit the previous divine beast bosses once you complete each champion challenge). Also, what do I want new armors for If I've already completed the 4 main divine beasts?
No new post-game content, which was what I was expecting (since the "good" ending points towards that), and no advancements in the story (just new insights about the deceased champions, at least as far as I've reached).
TldR: A good amount of content, but none of it truly new in terms of story or gameplay mechanics. Great DLC for anyone who is about to start the game, since it adds lots of interesting things, but not too appealing for anyone like me, who has invested more than 200 hours in the game and completed almost everything in the main game.