AMD is now enabling drop-in support for Zen 3 Ryzen 5000 CPUs across the entirety of the first gen socket AM4 boards including ones based on the X370, B350, and A320 chipsets. Motherboard OEMs can be expected to roll out beta BIOSs based on AGESA 1.2.0.7 in April, though it is unlikely that each and every 300-series board will get the update.
https://www.notebookcheck.net/AMD-bids-adieu-to-socket-AM4-by-extending-Ryzen-5000-Zen-3-support-to-all-300series-AM4-motherboards-including-the-A320-chipset.608094.0.html