In a silent event that occurred earlier today, AMD’s Chinese product page for the Radeon RX 580 graphics card now shows a new addition- the RX 580 2048SP. Contrary to every other RX 580 on the website, including OEM and system integrator solutions, this new SKU has 256 fewer stream processors (2304 vs 2048, respectively). As it turns out, this appears to be a China-only graphics solution that launched on October 15, 2018 and TechPowerUp can confirm this is a Polaris 20-based Radeon product as well.
Looking purely at the specifications, this appears to be an RX 570 with a higher boost frequency (up to 1284 MHz vs 1244 MHz), so this is a confusing strategy by AMD to call it an RX 580 instead. The tinfoil hat nearby suggests that this may well be taking advantage of consumers who go simply by the name scheme and do not look up what a stream processor is, and indeed this is similar to what AMD did last year with the downgraded Radeon RX 560 that started out to be a Chinese-region product and then found its way elsewhere as well. Retailers have started listing this as a product available for consumer purchase already, and a search for RX 580 brings up both these and the other versions together. Not cool, AMD, not cool.