Blizzard has announced that the Overwatch 2 midseason patch has been delayed while they resolve a critical issue.
The midseason patch would have brought the return of Mei, new cosmetics in the Overwatch shop, delivery of Overwatch League Viewership rewards, and balance update. The balance update included nerfs to Sombra, Genji, Zarya, and D.va. The specific Hero changes can be found here.