Sorry for not clearly specifying. I meant an asset pack! I sell assets.
That's what I meant: if you update a static tile, that's all good and well. But the people that already downloaded it an put it in a game, might have used for a static purpose. If you exchange that static tile with an animate one, you might break design - if the developer propagates the update into the game.
Putting additional things into a pack should not be a problem.