When we originally decided to allow questions about future events with regard to anime/manga production*, the onus was on the asker to demonstrate that an announcement has been made, at which point it is reasonable to ask questions specifically within the context of that announcement. In practice the vast majority of questions about future events are not of this form. However, if (for example) someone linked an announcement of the Zaregoto adaptation and wanted to ask whether only the original is getting adapted or also parts of the spin-off work Ningen, it would not make sense to close that question. Even if we can't answer it now (and I'm not sure whether we can), at some point we'll surely be able to. Most questions of this form will still be at least slightly interesting after the work has been produced.
If an announcement has been made but the asker is not aware of the announcement and coincidentally asks an answerable question, it's fair to close it anyway. Close voters aren't expected to know whether announcements have been made. Almost any "Will X get an anime adaptation" question falls in this category, even if the answer is already known. Of course, if an announcement has been made that the OP is not aware of, but it can be edited in to the question in a way that doesn't trivialize the question, that improvement would be grounds for not closing or reopening. This won't save the common "Will X get an anime adaptation?" questions, as they're trivialized by the announcement. So if someone asks "Will there be another season of SAO?" it's fine to close that question even if you know that a third season has been announced.
So, to put it briefly, allowing questions about announced future events is not supposed to allow questions where the asker happens to get lucky and an announcement has been made. It's supposed to allow questions asked within the context of an already-public announcement. That is to say, you can ask about the news, but you can't ask looking for news, as we aren't a news site. In practice such questions are rare, and the burden of proof of an announcement lies with the asker, not close voters.
*Note that in-universe questions about future events are completely allowed, as we can just wait and answer them when they are eventually answered in-universe (either explicitly or by lack of an answer at the conclusion of the work). The problem with production questions is that the vast majority of the information is not public knowledge. So we can never rule out, say, another TV season of Ranma 1/2 or Slam Dunk, even though it seems quite unlikely. In the rare cases where there is publicly available information (in the form of an announcement), it makes sense to allow questions about that information, but in the absence of any evidence to the contrary we can only assume that any information about such is private.