AMD is apparently planning another chipset for Ryzen 3000. The X590 chipset is supposed to place itself above X570 and probably offers more PCIe 4.0 lanes.
AMD has confirmed that there is no PCIe 4.0 for old motherboards. In the run-up there were hints that X470 and B450 with Ryzen 3000-CPU can handle PCIe 4.0.
Ryzen 3000 brings PCIe 4.0 to end-customer computers for the first time. Gigabyte updates now indicate that this also works with X470 and B450 motherboards.
The new Ryzen 3000 series will start soon. A new leak shows that Asus is planning 12 X570 mainboards for launch and is expanding the ROG Crosshair series.