The information was revealed by Dylan522p within the subreddit of r/hardware. The site labels the specs along with the performance of a device by the (code) name of “66AF: F1” which, allegedly, is the next-gen part based on Navi. This has been assumed purely because such an ID has not been seen before in AMD’s portfolio. However, while this device may be based on Navi architecture, it could also be something different altogether. For this reason, the leaks are being labelled as a rumor so far, though the results are very interesting.
Performance wise, it seems that the device is good in terms of graphics but not so much in the compute departments. Leaked information shows graphical performance roughly at Vega 56 levels, while compute performance is closer to an RX 580 8GB. However, it is still too soon to judge this as better or worse than Polaris since we do not know which price-point it will be introduced at, its target market, or even whether this information is reliable. Till then, we will have to wait and hope for the best as competition for Nvidia from AMD is desperately needed in the GPU market.