I don't think Capcom really puts any thought into who signs on the dotted line to voice what role, to be honest. So as long as the money pours in for them, that's all that matters.
It's a pity RE got to become a big franchise, where it got tarnished somewhat. I'm grateful it did come this far, because that's incredible how a franchise that started in 1996 is still going strong today with the sales and generally positive reviews. But at the same time, questionable decisions on Capcom's part has often made me ask myself as to why I still follow along.
I sincerely hope RE9 can get back to the more true side of the series, and therefore ditch this fantasy nonsense, because I don't want it carrying over from RE8.
And yeah. Every character is getting on a bit, ages wise. So there's that problem too.