Which Heores are Banned in the 2021 OWL Countdown Cup?

For the last regular season tournament in 2021, the Overwatch League is introducing one last set of hero bans. The 2021 OWL Countdown Cup will remove four new characters from the roster in order to shake up the meta from the previous tournament. Because Zarya, Sombra, Tracer and Ana were banned back in the June Joust, they were removed from the pool of characters that could have been banned. The Countdown cup will not feature Sigma, Ashe, Echo, and Lucio.