Indeed. If Kenpachi starts to believe in Zanpaktou, he might be able to learn his Zanpaktou's name!He can't learn it's name because he doesn't know how to communicate with it.
His zanpaktou was screaming, yet, Kenpachi couldn't hear it. In a way, you have to believe in your zanpaktou and trust it in order to learn it's name. You can't learn it unless your zanpaktou feels that you're worthy/ready.