The 400-series chipsets from AMD are expected to include the X470, B450, and A420. These chipsets will be launched alongside the upcoming Ryzen 2000 (Zen+) processors, which is a 12nm refresh of the current Ryzen lineup. The main change will be higher performance and better energy efficiency.
No new motherboard will be required as AMD promised backwards compatibility with 300-series motherboards, but the new 400-series will bring some new features to the table.