I can't imagine them using V again. Geralt was a character in his own right that had character traits that were handed over to you to play with. The world was built for Geralt to be in. V was built as a blank slate character to insert yourself into. There's no reason to keep them. I'm pretty sure they only gave the character a name so everyone else in the game could have voice lines for everything and refer to the character by name. It was an attempt to make it a smoother experience, but really, V was a faceless avatar for the player no different to the Fallout games. But because they did the thing with the name it's seamless and everyone sees V as a character, but they're all seeing them as a different character based on how they played. It was pretty clever and I'm sure they'll do it again.