No, it's not your fault. Your question was harmless. Its the other dude that was unnecessarily rude.Sorry for asking. Sometimes save file are the same and can work with update of games. But i'm not used to that kind of early access, so sorry if my question was innapropriate
Answering your question: Usually your save files are safe between updates, unless the dev decides to update the Renpy engine. If he does that, then you will need to start over. Which isn't really that big of a deal since you can just skip the scenes until you get to where you stopped.