As an older person who had her first forum experience on the Nsider forums (Nintendo) back when Pokemon was on the GBA, this does kinda feel like that (I actually had that same thought). Those forums shut down around the time the next generation of consoles rolled out. It's not a great sign that Bungie spent all that time redoing their logo, navigation, adding that Marathon area, but then didn't add a single sub-forum or category. It's completely possible they didn't do it because of some other reason (ex: maybe the Destiny 2 requirement couldn't be rolled-back in time) but who knows.