WCCF Tech reports someone from AMD confirmed this to a Reddit user at CES 2017.
The same Reddit user later confirmed by talking to AMD reps at their booth that the Radeon 500 series cards are actually rebrands of existing Radeon 400 series. Following is what he had to say after visiting the AMD CES booth:So basically, Radeon RX 560M is the same as RX 460M, the Radeon RX 570M is the same as RX 470M, and so on.
“The card IS an OEM version of the 470. I asked an AMD rep at their booth about it. The 500 series is an OEM rebadge of the 400 series, like how the 8000 series was to the 7000 series.” via Reddit