Reports coming from Taiwan and China reveal that AMD will collaborate with ASMedia in order to produce all upcoming motherboard chipsets, including the more affordable B550 and A520 for Ryzen 3000 desktop CPUs, as well as the upcoming 600-series chipset for the Ryzen 4000 desktop CPUs that are scheduled to be launched in 2H 2020.
https://www.notebookcheck.net/AMD-s-600-series-chipset-expected-to-launch-by-the-end-of-2020.450285.0.html