Asus recently decided to enable support for all four generations of Ryzen processors on its ASUS ROG Strix X570 motherboard. This means that everything from 2017's budget Ryzen 3 1200 to upcoming Ryzen 4000 parts will be compatible, thanks to a generous 256 Mb BIOS chip.
https://www.notebookcheck.net/New-AM4-compatibility-king-ASUS-ROG-X570-Strix-with-256-Mb-BIOS-will-support-ALL-AM4-Ryzen-processors-from-purported-Zen-3-Ryzen-7-4700X-to-Zen-2-to-Zen-all-the-way-to-the-venerable-Zen-1-Ryzen-3-1200.468982.0.html