There are certain questions that are in a peculiar situation:
The question is about a canon in-progress (either the series continues, ala JRRMartin, or Enderverse; or the author is publishing an ongoing canon reference - ala Pottermore).
The question has no good answer in canon TO DATE.
There is a reasonable non-trivial chance that in the reasonably specific date in the future, related areas of canon WILL be expanded due to #1.
To re-iterate, this is expected in a reasonably defined amount of time - e.g. we know Pottermore will be finished in 2-4 years; and the last book of Enderverse will be published in 2 years).
In such a situation, should we have a policy which strongly encourages posting a very explicit note - accompanying "no info in canon" answer - in the form of:
Please note that there is no canon information on the topic as of MM/DD/YYYY. However, it is expected that a new part of canon () will be released on date MM/DD/YYYY, at which point this answer should be revisited to verify if the question was answered via new canon.
This note would serve four purposes:
Let people know that "not all is lost" - e.g. the "no info" answer may not be final.
It lets people know precisely when the answer (possibly) is no longer correct. E.g. it puts an expiration date on it; anyone reading past that date would know not to rely on "no info" answer without checking new canon.
It would be a wonderful resource for improving the site content - people can collect answers with such notes as "TODO" lists and verify the info once the canon is expanded on a given date.
While I'm wishing for a pie in the sky, may be JKR will read such a question on SFF.SE and decide to include the info into Pottermore just because we noted this :)