It's within the "new posts" system (as opposed to within a forum):
View attachment 191857
The watched threads page is now just a list of the threads that you watch, though normally, unreads would generally be near the top (though not automatically, I know). There isn't an option to change this.
Since the first previews of 2.0 and since it's been out as a stable version, I don't recall feedback about this particular change. Indeed, 1.x had a number of questions about managing watched threads (as it required a separate click from the unread page).