Not necessary. Take a look at this example
SpriteA -> set height to SpritA.Height + 10
but You want to change it to
SpriteB -> set height to SpritA.Height + 10
Sometimes You want to change only an object but keep expression intact.
For what You want You could use
SpriteA -> set height to self.Height + 10 - that way expression will be valid for any replaced object.