Cable as we know today has a convoluted origin story, but the gist is that he’s the son of Cyclops and Madelyne Pryor who got sent to a bad future as a baby and came back a grizzled cyborg gunman. His vast telekinetic powers, which are held back by a techno-virus, was retconned into his character due to his connection to the Summers-Grey family.
However, that wasn’t intended to be the case. Rob Liefeld originally planned Cable to be the future version of Cannonball.
He wouldn’t have his jet propulsion powers because of his injuries, and his cyborg parts were there to show how he barely survived. That was the main reason he used guns, simply because he couldn’t access his normal powers. Cable under this concept wouldn’t have had TK abilities, either.
This was actually foreshadowed in X-Force #8, where he came back in time to recruit the New Mutants with a special eye on Cannonball. There was a memory gap, and there was to be a big reveal that Cable would learn that he IS Cannonball’s older counterpart.
Obviously, what was intended to be big foreshadowing never came to be, because Liefeld left X-Force after the 9th issue, and Marvel itself, to help start Image Comics. Thus, the concept of Cable got away from him, and his current backstory took shape. Cable being Cyclops and Madelyne’s son was a retcon based on an earlier plotline, established in Cable #6 (1993) by Fabian Nicieza
So... in a bit of speculation, say that Cable is Cannonball from the future and that sticks. What changes about comic book history? Anything notable? Thought it would be interesting.