Neither, it's just how the game works. Your mid-route save is the thing that will fuck up, the jar is a different file. If you finish the route (so you have all the scenes in that route) in the older build, those scenes will be unlocked when you go over the new version. Your save might not work, but the route is done and you got all the scenes from it, so why would you moan about having to restart if you got all you needed already ? That's a good reason to laugh at all the whiners coming around every build to cry their life away how restarting for like 10 mins every 4 months is the worst thing known to mankind
Now imagine the same thing but you'd have to do both Debbie and Jenny's route just to unlock the school. That would be a good reason to moan, but 15 mins every 4 months is just petty and highlights how fail some dudes can be