Oh REAL Owen can totally still be an awful man.
I'm just thinking since we are stuck with that solo as actual canon that nobody wants and Rogue has never tried to find/reconnect with her Father who is not actually dead and she has never divulged her surname ... what if he KNEW or at least suspected that Rogue wasn't actually his biological daughter? Maybe he even said something to that effect to her Aunt before he skipped town? He can still be an abusive slime ball.
Anyway, it's an easy way to make her Mystique's actual kid without making that Rogue solo a total fever dream ... which it basically was anyway. But faking the existence of Priscilla and Aunt Carrie, who helped deliver Rogue and raised her for a time, would be trickier than a shapeshifter posing as a trash husband for a single fateful night.
It would also honor something Claremont wanted to do with Mystique, if not quite the way he intended.
And if Destiny told Mystique to go boink some random woman in Mississippi in order to create a child that would one day save Destiny, you and I know Mystique would do it in a hot second. And it would explain why she was out there to conveniently collect Rogue later.