Today the MTG Arena team announced that Oko, Thief of Crowns will be banned in Brawl on Arena. Oko will not be eligible to be a deck’s Commander or appear in the other 59 cards. This has no bearing on the card’s legality in tabletop Brawl or Standard.
The next Banned and Restricted List update for Standard will be on November 18th, 2019. Mythic Championship VI, which features Standard, takes place this weekend – November 8th-10th, 2019.