The reason why your new thread (or post or comment or update of the community's activity) is because you need to hard-refresh (F5) the page you're on. It's been like this since the recent changes to forum behavior. As for what to show on a thread, that's all there. Even better, it has the most recent post date. If someone wants to know the date the thread was created, they can just look at the thread's OP, the first post.