We're 4 days into the OWL season and I'm already bored by the same pre-selected maps every series. If only Blizzard didn't hate the diverse map pick and ban system.
— Rod Breslau (@Slasher) January 13, 2018
Blizzard has always shied away from having a map veto system in Overwatch. The reasoning behind this is that they would probably want all the maps being played and create a better experience for the casual viewer. Having a map ban system would tilt the tournament choices towards particular maps.