As the Siegels and Shusters continue to fight over Superman, there’s a possibility that Kal-El has to retire or go away for good. Not because I hate him but because of the way the Superman franchise is heading would mean purging or excising essential problems.
The Superman case will be revisited again, which prompts DC to retire Kal-El and Krypton. In fact, by the time this happens the original Superman is dead for good and all of Krypton is gone.
That doesn’t mean there won’t be any Supergirls, Superboys and Supermen out there. All that it takes is a replacement or heir that would change the Superman franchise.
Not necessarily for better or worse, just something that happens in light of copyright and estates.