https://www.digitimes.com/news/a20190614PD212.html ASMedia will tape out its next-generation AMD-platform chipset silicon, and is on track to shipping its new chipsets to motherboard manufacturers by Q4-2019. This would pin availability of the first motherboards based on these chipsets to at least Q1 2020. These chipsets not only feature PCI-Express gen 4.0 downstream lanes, but also boards based on these will be built to AMD's PCB requirements for the new platform, enabling a PCI-Express 4.0 x16 slot for discrete graphics, and revised CPU VRM and memory wiring specifications that improve overclocking over the previous generation platform. For now there are two SKUs in the works, the B550, which succeeds the B450, and the A520, succeeding the A320.
These could be cheaper alternatives to AMDs X570 chipsets.