No, it shouldn't. SU had a plan, moved toward the ending they had roughly sketched out since the first season, completed the main story, then decided to throw in an epilogue showing what happened next for various characters.
The writers on Star vs. managed to convince some people they had a plan, even though in the final analysis they plainly didn't, and they slapped together something for a finale that was so bad it resulted in them accidentally giving their protagonist a higher death toll than all animated Disney movie villains combined. MUCH higher.
The people who stuck to their plan and told the story they wanted get to have an epilogue so they can go "now that you mention it, it might be good to show a bit of an aftermath."
The fucktards that accidentally did a genocide shouldn't get a follow up. They should be held accountable for writing the second-worst ending of any Western animation to get an ending. They should have to think about what they did.