No they wouldn't. They'd need to supply the DOCSIS 3.0 compatible modems, the router STILL couldn't care less.
Router, modem, i got mixed up. If they needed to supply a modem, i doubt they would do it for free. Great if they did, unlikely for free though. They will probably offer a one off cost for the modem and a free upgrade. But you would still need to pay for the modem, which would be fine imo.