Today there were two questions about when the next episodes of a TV-show would be aired.
On Scifi these questions were ruled off-topic, as Mark Trapp said over there:
I think they are two different types of questions, to be closed for different reasons:
In terms of release date questions, there's a knowable date after which the question becomes useless. Those types of questions are a great example of something that should be closed as too localized, especially on a site like SciFi.SE: it's self-obviated on release date and there's no clear and present need for knowing the release date ahead of time (unlike, perhaps, knowing when PHP 6 or Python 3 is coming out, which can dictate how to proceed with a development project).
In terms of rumor questions, I think your assessment is correct: they should be closed as not a real question, in line with Real Questions have Answers: rumor questions, by their nature, begin with the premise that the question answerers cannot speak with any authority about the subject matter; otherwise it wouldn't be a question about a rumor.
I'd propose we do the same here.