They could have kept everything intact but make them high res with better effects in eyes, lips, and skin. Because this isnt a huge graphical update anyway....

Unlike in some other games I have played where the graphic update really changed everything. So in my opinion if they want to make things the same, then make it the same (use old model as baseline) but with higher details. When it comes into character model, its either you do a big update (like WoW did) or a minor update (higher res, textures, and effects) imo. Something in between will always result in complains.

In some of the complains you can see how even changing eyes or lips a little resulted in a different character. Its neither here or there and just odd.