Something slipped through during the AMD Radeon RX 480 launch eve and many of us have actually overlooked the list, but not this redditor who managed to get this one snipped and publish it on Reddit. It could be a typo but there are those who believe that this could a hint from the company itself.
Another supporting material has been spotted on Reddit too, published 2 days ago where RX 490 can be spotted at the very bottom of the drop down list in the screenshot. HMB or HBM2 is definitely out of the question as 8GB GDDR5 memory has been confirmed on the RX 490, but what interests us the most is what wccftech.com suggests - the RX 490 as a dual GPU card. More info coming soon.