The new list includes not only the Radeon RX 460, Radeon RX 470 and Radeon RX 480, but also the unannounced Radeon RX 490. The webpage mentions these cards are eligible for the game promo offer if they're bought between February 15, 2016 - December 31, 2016, leading some to think that the RX 490 may be launched before the end of the year.
While not entirely impossible that a Vega-based Radeon RX 490 with HBM2 arrives before the end of the year, the "RX 490" on the list could be nothing more than a mistake. It's unlikely to be another Polaris-based model as AMD explicitly confirmed the Polaris lineup is complete with the RX 460, 470 and 480.