well, i have no evidence for what i'm about to speculate, but here goes:

In the early '60s, comic books and their creators were certainly on the edge of the emerging "counter-culture" --- amongst whose adherents the idea of blending high culture with low culture -- and of legitimating "low" culture like comic books, would have been very popular...

The whole concept of the X-men is very counter-culture, a group of "mutant" teenagers trained by the wheelchair bound but brillant Professor Xavier. Shades of Herbert Marcuse or C. Wright Mills, of Kinsey, of SDS -- not to mention the civil rights movement -- because the X-men are  "mutants" who are discriminated against by mainstream society and have to fight for acceptance through their brave deeds...definitely a lot of symbolism for the real events going on in the South, in Vietnam, on college campuses...

The writers of the X-men comic book would stereotypically have been beatnik intellectuals, smoking pot, involved or at least aware of radical politics, and readers of controversial writers like Nabokov. Just as Sting and the Police evoke Humbert Humbert in their song a generation later, the writers of the X-men may well have read "Pale Fire" and used the name as an allusive inside joke.

Nabokov in the '60s was a living, controversial, best selling writer not confined to the universities or the academy. The original paperbacks, as you can see from their covers, were marketed towards a mass audience; how different from the Vintage editions of today, with their tasteful and subdued covers that proclaim, "i am serious literature for a refined reader."  Back then, VN was on mainstream TV, made the cover of TIME magazine, and so would have been very accessible even to readers of comic books.