I'm confused Minnewaska.
After being logged on for a while if I click on new posts I get a bunch of unread threads (meaning threads with at least one unread post since I last logged on.)
If I click on 'quick links' 'today's posts' I get all unread threads from the last 24 hours.
Isn't that how it has always been or am I not understanding your question ?
“Life is a trick, and you get one chance to learn it.”
― Terry Pratchett, Nation