I agree with Jeansson.
A variable that can hold an object could come in handy in different situations.
Creating an object by UID is not possible as far as I know.
A possible use case is what I'm trying to accomplish in my current project:
I create 1 or multiple decks of cards, each card consists of a background, value, suit and face sprite.
This reduces file size considerably and offers much more flexibility in animating etc.
Now, I want the user to be able to choose different skins for the game. Instead of having to duplicate the function that creates the deck for each different skin, a variable referencing an object in the projectbar passed on to the function would do the trick.
Being able to create an object dynamically by string/name or UID would make that possible too. But another variable type for e.g. sprite/audio etc would be the best and would open up many more possibilities.