New questions:

Did 9-11 occur later in the Marvel Universe given that it's only been about a dozen years since Fantastic Four #1?'

How we reconcile the compressed timeline with the Christmas stories that show up most years? Surely Christmas doesn't happen multiple times a year in the Marvel Universe.

Very belatedly:

Andy E. Nystrom wrote:

Historical text from Facebook:
 
Andy Nystrom
June 8, 2018 3:28 pm
This thread is for questions that you're wondering about but which Handbook writers probably can't give an answer to, because the answer has never been revealed in a comic. So unlike the General Q&A thread, these are for questions you're not expecting a definitive answer to.
Starting question: In the first USAgent mini-series, a Scourge killed someone in flashback while Priscilla Lyons tailed him. Whom did he kill? Sadly we'll probably never know if Gru had anyone specific in mind, and to my knowledge no other writer has picked up on this plot thread.
Also, why do characters age at different rates (Julie Power and Cassie Lang seem to have aged faster than most adults). Likely Franklin related somehow, but never confirmed.

Real world - writers who don't get or don't keep track of the sliding timescale. It'd actually be interesting to track the various kids we've seen in the Marvel universe and see how their apparent aging scales up. I did this for Power Pack when I wrote both Julie and Alex's profiles, and realized that they actually tracked reasonably well considering things. 

In-universe - kids appearances change faster than adults, especially once they hit puberty. Plus we've got weird biologies in comics - who knows how exposure to Pym Particles or Kymellian life energies might change the aging rate of a human child.
​

Andy E. Nystrom wrote:

Reply 1.
Luke Van Horn
This would likely apply to a lot of questions about licensed characters or intercompany crossovers, right?
Reply a.
Andy Nystrom
Handbook writers can correct me if I'm wrong, but I imagine it depends on if the answer was put into print prior to losing the license. If the answer to a question is found in, say, Savage Sword of Conan #78 or Superman vs. the Amazing Spider-Man, I don't see why they couldn't cite that and answer the question.

Yep, We can mention and cite stuff seen in licensed titles, which is why entries have explicitly named Conan, Godzilla, etc. despite coming out at times when Marvel no longer owns the license. Intercompany crossovers where both parties have ownership rights are a bit less certain; we probably could mention characters by name (though not Marvel, the Invincible Handbook gives an example of this, as it mentions Spider-Man by name), but we prefer to play it safe and have fun with it at the same time, hence referencing (for example) Impossible Man meeting Mr. Myxzptlk by saying Impy encountering an imp from another dimension that he called Mixed Pickles (here Impy helped as he did actually call Mxyzptlk that in story). 
​

Andy E. Nystrom wrote:

Reply b.
Luke Van Horn
Yeah, I meant asking questions that aren't explicitly answered on the page
Reply c.
Andy Nystrom
Yeah, those are likely a source of a lot of potential questions. Also cases involving a Marvel-owned character with no active profile and not under any editor's domain for quite some time. Top Dog or Petey the Pest, for example.
Reply d.
Luke Van Horn
Yeah. A prime example: is the Lizzie character in Little Lizzie volume 1 the same character as the Lizzie in Little Lizzie vol. 2? They don't look anything alike and have different supporting casts, but it would be weird to relaunch the series just a couple years after the first volume ended with the same title but entirely different characters.
Reply e.
Andy Nystrom
And in interviews, it's been said that Petey grew up to be Henry Peter Gyrich, but this has never been confirmed in a Marvel story.

In some of those cases we do sometimes check - I'm fairly sure we looked into the Gyrich example, but couldn't get a definitive answer.
 

Andy E. Nystrom wrote:

Another "probably can't answer" question: When Roderick Kingsley first appeared he seemed a lot more effeminate than he later did. This may be part be due to the goblin formula, but he also has a brother Daniel with a somewhat similar personality to his earlier one and who has impersonated Roderick. Could Roderick's earliest appearances actually be Daniel in disguise?

Not impossible I guess. One to ponder and maybe mention to the other handbookers.