It seems Biostar was a little careless and accidentally published the specification of its upcoming BIOSTAR X570 RACING GT8 motherboard. The AMD X570 based motherboards are expected to be introduced at Computex in Taipei within a week or two.
This new high-end model from Biostar has 12-phase VRM and supports up to DDR4-4000. The specifications sheet reveals PCI Express 4.0 support, but the information suggests this is only for the M.2 interface. Other than this, you get three PCIe x16 slots and three PCIe x1 slots. The motheroard has a single Gigabit Ethernet port and features a DVI display output for APUs with integrated graphics.