Yeah I've been saying for a while now that a compromise would have been possible since time travel is now a part of Jon's story. This is literally a situation where they actually could have pleased everyone. But chose not to.
Either bring the real Jon back and have older Jon exist as the Superman of the future. Or pull a Future Trunks (Or you know...what the X-Men have done multiple times) and just have them exist in the same time, with their own separate adventures. That actually would have been pretty neat seeing the obvious shift in timelines that would create, and seeing how he grows into someone different from his alternate future self.