However, there's one notable exclusion: canon in progress.
More specifically -
If a specific canon has some published works already
And it also has some future works (planned, maybe, or unknown)
And, the question is phrased specifically so that it can be answered in the context of already published works
Then, such question is not FWP, even though in theory there are future works that may alter answers to such a question.
Just to be clear, any questions very specific to not-yet-published canon are still FWP, as per the first rule.
To clarify, specific examples. Assume the time frame to be 2018, after release of Star Wars episode 7 and 8, but before release of Episode 9. And we don't yet know if they will do 10-12 aside from vague rumours.
"In Episode 8, did Spoiler spoiler the Spoiler?"
OntopicOn-topic, since Episode 8 is released.
"In Episode 9, did Spoiler spoiler the Spoiler?"
VTC as future works, since Episode 9 is not released yet; and the question cannot be answered well from episode 8.
"In Star Wars, did Spoiler spoiler the Spoiler?"
OntopicOn-topic, since the answer isn't bound to unreleased works. We can answer it based on Episodes 1-8.
"No answer known yet but may be revealed in future works" is an excellent answer but NOT a valid reason to VTC
This is a bit difficult to do with precision in all cases, as some questions may be borderline (in a sense of, it may ask about something technically about Episode 8, but to any canon expert, it's clear that the answer will be unknown till Episode 9 - personally I'd be OK with FWPing such a question but wouldn't be heartbroken if it stays open).
To try to illustrate by example again:
"Did *Character who was seen dying in Episode 8" really die?"
FWP, since the answer is impossible until Episode 9 is released.
"Who are Rey's parents?"
VALID. NOT FWP. Because even though we may have a better answer from Episode 9, we already have enough canon info from Episodes 7-8 to be able to answer this.