I hope they add more BitterBlack Isle type content, end game enemies (including some that you don’t see in the main game) that get tougher the more you progress, with awesome loot and rewards, even better if they add consequtive rounds with even stronger enemies after you clear the area
If the leaks are to be confirmed then the moon tower they originally wanted to put in (which then got retooled into BBI and the Everfall) is likely going to be brought back, so this is one of the things I'm least worried about.
The only thing that really gives me pause right now is the fact that they seem to have removed the ability for each class to have multiple skill palettes, with your palette switch button now being replaced for a unique class skill, meaning you have 4 skills to play with instead of 6.
of course they might have changed the palette switch button so that now you have 8 skills instead of 6, but the flipside of this is that reducing your skill palette by 2 means as you're more limited in terms of how you can approach combat, you'll start thinking more about the environment and how you can use it to your advantage: missing two skills on your hotbar might encourage you to do things you might not normally do, like grabbing enemies for your pawns to finish off, going for concussions by getting big enemies to run into walls, using rivers to wash enemies away, destroying bridges while enemies are still on them etc etc.
I had this experience with NioH 1 and Nioh 2, actually. A lot of the playerbase prefers NioH 2 because it has more content and hence more options to deal with each encounter, but as a result there's a lot more methods available to approach content which are completely broken so the content ends up being less challenging as you have to think about what you're doing less. In NioH 1, you don't have the luxury of spirit summons, auto-counters which can cancel into anything form anything at the click of a button (technically DD does have this in the form of reset, but that's class specific) so you have to approach each encounter a lot more carefully, meaning the game felt more rewarding to complete.
Time will tell, I guess. man I love DD.