It could, and maybe someday will. But it would be a headache to nove all the existing threads, and there really isn't much advantage toi it other than symmetry.
It would probably be a good idea if there were as many novels as short stories being posted, but I don't think that's the case right now.
If you want to attract genre-specific readers to the piece just inlclude e.g. (Sci-Fi) in the thread subject.
