i'd love that too. But the plot is,
This is a survival server. It was created on the basis of keeping it Vanilla - friendly! I don't think that would be a good implementation on the name of pure Minecraft. And also, as we already know, the server has been made so that almost everything is not related to p2w. And I am pretty sure /rename would also be a command only ranked players could use.
So these are my suggestions.
-Jeff