As I'm looking more closely on Stash, I think the new text is a bit confusing. Of course I know how it's supposed to work: You get to look at the remaining cards in your deck, meaning the cards you're not shuffling, before placing Stash. A player has to know about the new shuffling rule for this text to make any sense of course, and even then it has caused some confusion. But I wonder if it's even technically correct.
When shuffling this, you may look through your remaining deck, and may put this anywhere in the shuffled cards.
Usually, "when" means "after", so "when shuffling this" should mean after you've shuffled. ("Shuffling" must refer to just actually shuffling, so before you add the shuffled cards to your deck.) So, after shuffling your discard pile, you may look through your deck, and then you fish out Stash and place it anywhere in the shuffled cards. Then you add those cards to your deck. This works fine.
But what about Inn, Annex and Donate, where you actually shuffle your deck? You are told to shuffle some cards into your deck. So you first add those cards to your deck, then you shuffle your deck. This is different from the normal shuffling, because normally the cards you shuffle are not in your deck. Going by the above, Stash now lets you look through your deck after you've shuffled it, and then lets you place Stash with complete knowledge. I assume this is not intended?
We could assume that the meaning is rather "when you would shuffle this". So the first thing you do is always look through your deck, before shuffling. But you don't do the next instruction until after you've shuffled (which is clearly indicated by "in the shuffled cards"). So the interpretation is something like: When you would shuffle this, you may look through your remaining deck, and then after shuffling, you may put this anywhere in the shuffled cards.