Some space could be saved ditching some assets like the warnings from the saved not working since previous updates, I doubt someone have savefiles from then, and even if they did, why
I mean... I agree it's not necessary, but saving space? That would save a few kilobytes. The game is almost a million of those.
Like. Save files are a few hundred kilobytes each. If you're that stingy about saving space, you can do a lot more by just never saving.
But it would save space in our miiiiinds! 😉