Time travel? As an X-Men fan, really, you don't want to go down that road. Honestly.
It all started innocently enough, with Rachel Summers spinning out of an amazing and now-classic story way back in the early 80s, and ended up with a convoluted mess of alternate future refugees and multiple conflicting timelines and time-addled plots that even hardcore fans get a headache just thinking about it.
Next time you think the Huntress revamp is bad, just put yourself in the shoes of those people saying to themselves "for fuck's sake, couldn't they have just made Cable someone else entirely? Preferably not from the future, and without two clones and a space computer and whatever the hell is up with the Askani thing? And while we're at it, where in the hell does Bishop fit into this? Do the Sentinels take over everything, or is it Apocalypse, or is the future run by mutant cops? Does anyone actually know? ARRRRRRGH!"
You don't want to open that particular Pandora's Box.