I know we have a flaired user whose specialty is comic books, but even if they don't see this hopefully someone well-versed in pop culture will.
I know that mutants have long (always?) been an allegory for racial issues in the X-Men comics (and superhero comics generally, no doubt), but of course the concepts of a kid "discovering" he's a mutant during adolescence and either "coming out" or "remaining closeted" cannot be about race. In one of the X-Men movies, there is a scene that makes the connection between these concepts and homosexuality clear (the scene with Bobby Drake's family), and I got the impression from fans that this wasn't new. How far back does it go? How far back in the comics is the manner and timing of one "getting" one's powers established? Has it always been thought of in terms of LGBT struggles? What do we know about these early writers' political beliefs?
I figure it's entirely possible that, depending on the answer, this question may violate the 20-year rule. So as a backup, I'm also curious about the racial themes I mentioned earlier, and how and when that became a part of the X-Men story (and again, presumably superheroes in general).
From the very first appearance of the X-men, they were students at a school for "gifted youngsters." I think in X-Men #1 (1963) (and definitely in the original run) they were referred to as "children of the atom."
So adolescence has been, so to speak, in their DNA from the start, as has the idea of being kind of freakish, misfits, "different".
Everything else is subject to a certain amount of interpretation - even who should be credited as creating them. This was a Stan Lee/Jack Kirby comic, and while in later comics work there was a clear divide between an artist and a writer, for a lot of these early Marvel titles, how much was Lee's idea and how much was a Kirby invention is... a subject of a great deal of contention.
Their political beliefs are fairly similar - for the 1960s, they'd both be considered middle-left populists, I think, and nearly all of the Marvel comics were... well... kind of standing up for nerds and braniacs. Scientist heroes were the thing. Look at Reed Richards, leader of The Fantastic Four (Marvel's flagship title then). Look at Peter Parker, the picked-on, over-smart and under-earning hero of Spider-Man (who hit the scene in 1962).
Now, the potential and assumed links between homosexuality and comics goes back farther than Marvel, to Dr. Frederic Wertham and the congressional hearings in the 1950s over, in essence, whether or not Batman and Robin were gay and whether Bruce Wayne was a pedophile. (The weirdness behind Wonder Woman's origin was not helping.)
So... at this point in comics, anything out of the sexual mainstream was going to be heavily coded. There might have been some coding going on with the way Beast is portrayed in the early stories... but it's under a pretty heavy disguise.
There's a lot more to get into with what may or may not have been going on in some of the first X-Men stories. Like, I know that recently Stan Lee has said (and, bear in mind, he's not always the most reliable source for his own history) that the conflict between Magneto and Professor X was based on the differences between Malcolm X and Martin Luther King Jr.....