On the one hand, I can see that the developers' objective has been to stay as faithful as possible to the original models, and as such they may not really see the need for it. But although I think there has been some great work done in this area, they haven't been entirely successful with the fidelity to old models. Indeed, that is a very subjective assessment, too, and what you liked in your character's old face might not be evident in a new face. Depending on the skintones available, given that Chris has teased potential others, you may want to alter that too. Hair style and color can, of course, be edited in the game.