AMD has announced that the Ryzen 4000 processors, using the new Zen 3 architecture, will be officially revealed on 8 October 2020. 

The new Zen 3 processors will use a 7nm process, but little else has been confirmed for the next-generation desktop chips.

Rumours (via Yuri Bubliy) suggest there will be a 10-core chip arriving as part of the new generation, while many are expecting the range to max out at the same 16 core count as the current processor generation.
…
Continue here:
https://www.trustedreviews.com/news/amd-ryzen-4000-release-date-price-performance-specs-4004823