You should unlock the files again. It did literally nothing to stop the mod you were trying to stop from being brought over to the newer version, it just makes it harder for the end-user that wants to personalize their experience (such as with the old anthro sprites, their own recolors or just wanting to take a look at game assets) and if anything will encourage people to seek out their modded version as you can easily edit the sprites there. So, in effect, you actively promoted your worst enemy by inconveniencing regular players.