Prodrive have already confirmed they will not be appearing in Monte Carlo. And a far as I am aware, Prodrive never put in a request to the FIA to modify the gear shift of the John Cooper Works WRC.
That said, Kubica could split his efforts between the WRC and ERC if he only wants to do the WRC’s tarmac events. Monte Carlo, Germany and France do not clash with any of the events on the ERC calendar, though he would have only four days to get from Rally France to Rally Sanremo.