No, a BIOS update isn't required for a Ryzen 3900X on an X470 motherboard.
No, a BIOS update isn't required for a Ryzen 3900X on an X470 motherboard.
Confirm with the vendor that the package includes a "Ryzen 3000 ready" label; if present, it should work. Otherwise, an update will be needed.
Cost-effective options with appealing designs. Could the Gigabyte X570 Aorus Elite fit?
Yes, that's correct. Any item in Tier C and higher (or Tier B for overclocking) from the provided list applies.
Make sure you look at the manufacturer's site for your specific model to find out about BIOS updates.