I'd be shocked if Mitsubishi did this, unless the Mirage becomes the next 'in' car and they start selling 5000 of them per month.
It takes A LOT of money and investment to not just develop a new motor, but also to get it certified for sale in the US. They aren't going to do that to sell 20 'Mirage Ralliart Turbo Evolution' models in the US every month.
Besides, nobody would pay $20k+ for one anyway. We had better get used to the idea of the Mirage being an econobox, as Mitsubishi has already said their days of manufacturing hot rods are over.