Yes, PLEASE put it back! :O
Etruscan, if you scroll to the bottom of a subforum there is a key for No New Posts / New Posts / Hot Thread (No New) / Hot Thread (New). Clicking on “mark all topics as read” turns all the gold with star new posts symbols into white with no star. On the Forum level the same thing happens with the folder icons. Some of us like to use it to ‘clear’ out the threads we’re not following and easily tell what’s new on our next visit. 🙂