A few days short of a full year, AMD  rebranded the Radeon RX 500 series for OEMs. Bear in mind that back when it was launched, on April 18th, 2017, the Radeon RX 500 series was pretty much based on Radeon RX 400 series graphics cards with the same Polaris GPUs but on a more refined 14nm manufacturing process, calling it the Polaris Evolved.
It appears that we won't have to wait until June/July to see a five to six percent performance improvement as it was seen in a rather blurry crystal ball, as these are just simple rebrands for OEMs, something that both AMD and Nvidia have been convicted before..