Thanks for your recent feedback. Discourse, our new forum platform, undoubtedly displays threads in a different manner as compared to the old system, vBulletin. As opposed to everything on a single homepage, the new homepage separates threads into different buckets, based on some parameter (explained below), but all still accessible from the Forums homepage.
I'd like to point out the new navigation menu that lists the following views : Categories, Latest, New, Unread and Top
Categories View - shows all topics/threads group by category and subcategory
Latest View - shows topics/threads with recent posts
New View - show only new topics/threads created in the last few days
Unread View - topics you are currently watching or tracking with unread posts
Top View - most active topics in the last year, month, week, day
Also, if you ever forget what each view displays, move your mouse over one of the icons to display a tooltip that explains exactly just that. I think you'll find this new way of displaying threads helpful.