https://www.tweaktown.com/news/65560/amd-launch-next-gen-navi-graphics-cards-e3-2019/index.html
The full launch for Navi will be on 7/7 which has been previously rumored, as AMD will be using the number 7 considerably over the coming months since it is the first company to 7nm with CPUs and GPUs and it plans to capitlize on that. It makes total sense and anyone that looks at the situation would agree AMD would be stupid not to use the 7 card throughout its Zen 2 and Navi architectures both deploying on 7nm.
As for performance I've heard that we are looking at it easily beating the Radeon RX Vega 64 and coming close to the RTX 2080.