Anyway, if you think about it, it could be Generation Six. Remember that Generation Two only lasted for three years, and that Munchlax was unveiled way before Diamond and Pearl were released. So if anything, at least, I think there might be a hint that Generation Six at least exists in some form.
Why do so many people think that Gamefreak or any other game developer think they always have to follow patterns?
I highly doubt that any of the past gens were released when they were because Gamefreak was trying to follow a pattern, but rather they just released them when they are done. Some games just take longer to develop then others.