I can't see why you would need it. If you intend to use a USB drive then you will use the EZ flash 2 utility. Make sure you have an unzipped version of the newest BIOS on an un-partitioned USB stick, insert it, boot to the BIOS and choose the EZ flash utility in Tools. Choose the file and follow the instructions. It's very easy.
The only reference I have in my Asus M5a99x EVO MB manual for the support DVD has to do with copying a "freeDOS" environment to the USB drive for a DOS Boot. Unnecessary!