Yeah, I know.
But for most people just updating the game works.
Only time it didn't work was when Arc lost his dev keys and the thing was complaining the signature wasn't the same.
With this game normally it works and the only errors while installing tend to be not enough space.
Some seem to be fixed by installing with SAI for some reason, I recommend it because at least it will tell you a proper error message instead of just saying "No, can't install"
But yeah, ideally people would backup their saves.
It's just a bit more involved, and not every file manager works (at least back then when android 11 and the restriction were new)