Could it be this new name is also the name of the City of God?
Rev 3:12 The one who conquers, I will make him a pillar in the temple of my God. Never shall he go out of it, and I will write on him the name of my God, and the name of the city of my God, the new Jerusalem, which comes down from my God out of heaven, and my own new name.
BTW this "new name"....the bible does not say it is a new name. It just says he has a name written that nobody else knows