The predictions threads effectively become a discussion thread once the majority of posters are able to download the full chapter - it's just the normal flow of conversation once a chapter comes out. Also, people can check back in the same thread to see if their predictions were right. Granted, I don't think anybody does that too much here, but it's just there for convenience's sake.
Not everybody checks and joins on the Spoiler threads, and these threads also go on at the same time, roughly, as the latter part of the Predictions thread, so to merge Spoiler threads into anything would be chronologically mixing up the posts and ruining the flow of the conversation. Not to mention it would be predictions and theories and thoughts mixed with finding out what actually happened. Granted the spoiler discussion threads are sometimes more interesting than predictions threads, though, but most of the times they're just reactions to the spoilers coming out. Sometimes (not lately, since Touch's been so good at finding spoilers) the Spoilers thread actually will have nothing in them.
We could turn the Spoiler discussion threads into the Discussion threads, but I'd rather just start a whole new thread than pull the spoiler threads out of the Spoiler Section.
If the community believes that it might be better just to separate the Predictions threads from Discussion threads in the Naruto section, we'll do that. It would mean more threads, but it could be a better deal for everybody. But in other sections, there aren't nearly enough posts to warrant that kind of separation, so the Naruto section would probably be the only candidate at the moment.