Maybe the galaxy thinks he is dead but I think the ideal would be to have him in self exile. A batman like figure that appears and disappears out of nowhere, helping out around the galaxy as a form of penance. A symbol.
As cheesy as it sounds, this is kind of what I would have wanted. Rey and Ben wouldn’t be hooking up in secret or anything, he’d just become a wandering fighter for justice, trying to right some of his wrongs. Potentially with his mother’s lightsaber.
Obviously there’s no way to make that happen in an edit, but it’s what seems like a feasible story decision to me. He DEFINITELY could not join up with the Resistance and be like “It’s cool, I’m a good guy now!”
Should be noted that Driver specifically said that Kylo-Ben’s story would not end the same way as Anakin’s.
I suspect, back when writing TFA, JJ and KK MIGHT have considered Kylo living at the end. Unfortunately, the overwhelming pressures of Disney needing the usual stereotypical bad vs good storyline ending meant that they didn’t want to take the risk and, yep, bad guy dies, good guy lives.
At the Lucasfilm purchase, someone at Disney (Maybe Iger?) likely wanted a completely blank franchise to start over with. In the planning stages, however, they were convinced they shouldn’t risk rebooting everything, so they did the safer nostalgia-based soft-remake. Hence all the interquels as well.
Suppose if you were to remove the existence of the OT completely. As in, this is a completely new SW universe.
Under Disney, it would’ve ended exactly the same as it did. Good guy lives, bad guy dies.
I personally would’ve found it brave if they’d let Kylo live. It may be possible to do an edit where he goes into exile, like Jon Snow did. If anything, Kylo should’ve been the one to vanish into the Tattooine desert while Rey goes off with her friends.