I also think that whoever is in charge of the graphics in the game should establish themselves in an art director role and oversee continuity in art style going forward. If we are to maintain the old style, then all models should reflect that same old style. Otherwise, we will get very jarring clashes between new and old content.
Also, I personally would prioritize adding new content in the old style instead of overhauling the old style into something new. I find that people get too ambitious when trying to "reinvent the wheel" and they lose interest while not really doing much in advancement (updating graphics vs adding new content). Just my 2 cents.