I think it would be super cool if it was a rotating thing, letting fresh blood tackle the voice for every new game. As opposed to, say, just having a singular soundalike do it until they're also ready to retire. Of all of the big video games characters, Mario's
probably the easiest to do this with since he doesn't usually speak and it shouldn't ever genuinely detract from the experience.
Charles is 67, so hopefully this is more just a retirement thing than a health thing. Also hopefully the Monkey's Paw doesn't curl here and we don't end up with Chris Pratt or something at any point, a la Kiefer Sutherland's Snake.