Hmmm, Well, for starters, there really wouldn't be any reason to do that.
If you have a brain and play the game, then you should know how much momentum you have.
If this is added, it also risks crashing games.
When a player enters the server while a match is going on, the gameplay and movements are not accurate as to what is happening for real. Having a ghost showing different than what is happening on screen could cause lag and file conflicts.
For now, I'm against this idea.