Morrus has made all manner of subforums over the years-- opened new ones, closed or merged old ones etc. It really comes down to how much they get used. If a subforum only gets a half-dozen people posting in it and the front page has still has threads that were started six months ago because nobody is making new ones to knock them off the front page... that's when it gets closed and merged to one of the other ones.
The 'Dungeons & Dragons' forum is usually for the newest book released, as that is what most people are playing and have the most discussion about. So it will become the forum for 2024E when it gets released. Will the 2014E book trio need its own subforum then at that point to separate those people and discussions out from the 2024E players? We don't know... we don't know how many posters will be forsaking the 2024E books and sticking with 2014E-- and if there are enough to support its own subforum or if the 2014E books end up being better served in the current 'Dungeons & Dragons' forum, or moved to the 'D&D Older Editions'. It comes down to the number of threads that get made and what's the best use of space.
The 'Dungeons & Dragons' forum is usually for the newest book released, as that is what most people are playing and have the most discussion about. So it will become the forum for 2024E when it gets released. Will the 2014E book trio need its own subforum then at that point to separate those people and discussions out from the 2024E players? We don't know... we don't know how many posters will be forsaking the 2024E books and sticking with 2014E-- and if there are enough to support its own subforum or if the 2014E books end up being better served in the current 'Dungeons & Dragons' forum, or moved to the 'D&D Older Editions'. It comes down to the number of threads that get made and what's the best use of space.