Specs from Gigabyte say no.
https://www.gigabyte.com/Motherboard/Z370-AORUS-Ultra-Gaming-rev-10/sp#sp
CPU support list says yes(since bios f13). Me thinks they didn't update the specs when 9th gen was released.Specs from Gigabyte say no.
https://www.gigabyte.com/Motherboard/Z370-AORUS-Ultra-Gaming-rev-10/sp#sp