I'm definitely for separate threads for important news. The "Official" threads get really OT and hard to manage as mods. It's a trend lately, I've seen it at other boards I visit and sometimes I ask myself, "Why?" I tend to only read relevant posts for other artists (releases, articles, etc).
If you want to discuss random things about the artist, an artist-centric posting board is the way to go. For instance, since this is an Ayumi forum, there are many more specific threads for various stages of Ayumi news.