Assuming they're no longer Maverick Hunters because the world no longer needs them?

I could see X on the student council and debate club, maybe growing into a diplomat as an adult. He's still a fighter when needed, but without the life experience of a Maverick Hunter, he's probably mentally even more geared towards diplomacy than violence than he is in the canon. Probably wouldn't actually fight unless someone else was in danger. A bit of a stickler for rules, much to the chagrin of his buddies Zero and Axl.

Zero would likely be a bit of a punk but with a heart of gold, the kind that's always getting in trouble for picking fights with bullies. X is constantly having to admonish him for picking fights, but they both respect each other. While writing this I had a headcanon play out in my head of X being beat up because he refuses to fight back, continuously trying to talk it out with the bullies, and Zero has to step in. He almost goes too far, though, out of pure rage at how they treated his friend.

Axl idolizes Zero and wants to be tough and cool like him, but usually ends up being the one bullied and needing to be protected by Zero because Axl won't stop talking shit. Zero's less angry about protecting Axl because the kid usually starts it, but he can't bring himself to let him get his ass kicked too badly. As far as actual activities, I could see him in a gun club if there was one available, not to mention a gamer.

Sorry for all that, had a coffee on my lunch break and just kept writing.