Kaffis Mark V wrote:
I'm not seeing a big problem bringing back mutants into the fold if Fox ever relinquishes their license. In comic continuity, the Inhumans are genetically engineered from humanity by the Kree to boost them along the evolutionary process. Mutants, meanwhile, are the natural evolution of humanity along a roughly parallel path, millennia later. In the comics, all mutants share certain genetic markers and traits (which is where most every experiment Beast does and plot devices like the mutant plague come into play), as outrageously improbable that individual mutations would exhibit such common behaviors is from a scientific point of view. So there's a technical difference between a mutant and a post-terrigenesis Inhuman at a genetic level, though they tend to present similarly (random manifestation of superpowers and/or physical attributes).
In the MCU, Inhumans (if I'm remembering revelations from season 2 correctly) are implied to have trace amounts of Kree in their ancestry, providing them the ability to survive exposure to terigen, which spurs mutation in them akin to the comics. In order to bring mutants back into the MCU, all you do is... make mutants in the natural human population. Get rid of the genetic difference in the mutations themselves, and now you can pitch the Inhuman / mutant divide as a cultural one. Have the existing "converted" mutants who are presented currently as Inhuman on Agents of S.H.I.E.L.D., like Quake and Yo-Yo, have a falling out with the Inhuman leadership (I've heard rumors that we're going to see more classic Inhuman characters turn up in season 4 anyways), which breaks off to go found Attilan or whatever. Now, you have mutants identifying as mutants (and non-trace-Kree mutants would welcome the chance to not associate themselves with the double-freak Inhumans, who are part alien as well as scary mutants), even if a few of them happen to have their mutations derived from terigen thanks to their ancestry. Does it get a little messy? Sure. If you run a mutant plague in my system, Inhumans are also susceptible. And there would be a few mutants who might have anti-Kree bias directed against them if word got out. But whatever, those are details.
I'm with you, as far as the ability to define the differences and perhaps retcon a few current MCU characters if needed. While I'm not as well-versed on the background of the Inhumans within the comics, I know enough to see that Marvel went about he MCU stuff with care.
The things that make me skeptical are wrapped up in the fact that these other Fox-controlled characters should 'be around' already, and SHIELD would have tabs on them. Let's say the rights revert to Disney. How do they deal with all the backstory and history that is involved with the X-people that now can't fit in the MCU because they would be 'new'?
You'd have to either come-up with alternate origins for many of those characters, or employ some major hand-waving as to why these X-guys have been around all this time but no one noticed them. Maybe Dr. Strange has been mind-wiping the world regarding these guys, because...?
Anyway, not impossible, but it would likely be a fine line to try and tread between keeping the MCU internally consistent and not pissing off all the comic fans. Which I imagine is already a large task!