It appears that BIOSTAR decided to unleash its X570 motherboard a bit too soon.

BIOSTAR X570 RACING GT8

Have you been waiting for X570 release at Computex? It seems BIOSTAR had enough waiting and they put an unreleased product in their product catalog. The X570-based RACING GT8 is a 12-phase VRM flagship AM4 motherboard. It supports DDR4 memory up to 4000 MHz.

The specs sheet confirms that X570 chipset supports PCI Express Gen 4, although this information is only mentioned for the M.2 interface.

The X570 RACING GT8 features three PCIe x16 slots and three PCIe x1 slots. There is only one Gigabit Ethernet port and it appears that the motherboard ships with a DVI display connector (for Vega-based processors).

The X570 motherboards are expected to be officially introduced at Computex.

Source: Biostar (PDF)