Why would that be impossible? I'm sure there would be some way to do it, if a little glitchy.
Don't argue if you don't know how the system works.
Reason it cannot be done:
setShapeName is no longer allowed to be used, thus, you cannot set a different name atop the player's head.
However, this function calls something called .getPlayerName, which could be parented for bots and have the player control a bot as if it were a normal player. Oh wait! You can't overwrite getPlayerName! Oh look it's impossible.
(And even if it were possible, I'm not going to say anything due to the fact that someone will just abuse it and then that feature will be taken out, which could've been used for something productive.)
As far as I know, that's possible.
Without client sided mods, impossible.
With client sided mods, able to be bypassed.