Blizzard has released new Overwatch patch and introduced in new seasonal event Winter Wonderland, Symmetra and Zarya balance changes, and bug fixes, etc. Bellow are the details.

Winter Wonderland

Overwatch is getting into the holiday spirit with a brand new seasonal event. For the next three weeks, Hanamura and King’s Row will be decked out in holiday lights, we’re introducing a new collection of holiday-themed cosmetic items, you can challenge your friends to a snowball fight, and our Loot Boxes will be and tied with festive bows.

Grab a mug of hot cocoa and jingle all the way to Overwatch’s Winter Wonderland.

General Updates

Added a new “Boop” unlockable voice line for Sombra
Players can now select the 1v1 Mystery Duel and 3v3 Elimination game modes from the Custom Game menu
Added a “Stay as Team” feature, which allows players to remain grouped with their teammates after the match has ended

Symmetra

Photon Barrier (New Ability)

Replaces her existing Photon Shield ability
Generates a large energy barrier in front of Symmetra that blocks enemy fire as it travels forward
Shield Generator (New Ultimate Ability Option)
Symmetra's Ultimate ability now offers a choice between Teleporter and a new option: Shield Generator
Shield Generator places a device that grants additional shields to allies within its effective radius (regardless of barriers, walls, or obstacles between them and the Shield Generator)

Photon Projector (Primary Fire)

Range has been increased from 5 meters to 7 meters

Sentry Turret

Turrets that can be carried have been increased from 3 turrets to 6 turrets
Cooldown has been reduced from 12 seconds to 10 seconds

Photon Shield

Replaced with the new Photon Barrier ability

Teleporter

Health has been decreased from 200 to 50
Shields have been increased from 0 to 350

Zarya

Particle Barrier/Projected Barrier
Attacks like Reinhardt's Fire Strike or Hanzo's Dragonstrike that deal damage to both the barrier and the hero within the barrier, no longer deal damage to the barrier twice

Bug Fixes

General

[PS4 Pro] Fixed a bug that could obscure or hide UI elements on a 4K display
Fixed a bug that allowed more than one player to select the same hero on the Assemble Team screen, but forced one player to reselect after spawning
Fixed a bug that forced players to join Play vs. AI matches when attempting to spectate a friend
Fixed a bug causing a black screen to appear if players switched heroes as the round ended
[PC] Fixed a bug that allowed the “H” key to close the Hero Select screen even after that function had been bound to a different key

AI

Bots are no longer able to use abilities or attack enemies after a Control match has ended
[Console] Fixed a bug that prevented Ana from being selected in 1v1 matches

Arcade

> Fixed a bug that prevented players from correctly receiving experience after joining an in-progress 3v3 match
Fixed a bug preventing BattleTags from being displayed correctly during Highlight Intros and Plays of the Game in 1v1 and 3v3 matches
Fixed a bug causing the respawn timer to remain visible during 3v3 matches

Competitive Play

Fixed a bug that allowed more than one player to select the same hero in rare situations

Heroes
Fixed a bug preventing the nameplate above D.Va’s mech from disappearing while being destroyed, and displaying a “0” instead of the player’s name
Fixed a bug causing the “You” indicator (which typically only appears during killcam footage) to appear when D.Va looks directly at the ground
D.Va’s video tutorial now includes changes made to her Defense Matrix resource mechanics
Fixed a bug causing Genji’s sword to clip through its scabbard
Fixed a bug causing Junkrat’s Steel Trap animation to play when detonating a Concussion Mine
Fixed a bug causing Reinhardt’s hammer to become invisible to some players after using an emote
Fixed a bug that interfered with the accuracy of the alternate fire for Roadhog’s Scrap Gun
Fixed a bug that allowed players' Ultimate ability voice lines to play uninterrupted, even if they were hacked by Sombra during use
Fixed a bug preventing the sound effects from Torbjörn’s hammer from being played when his Ultimate ability was activated
Fixed a bug causing Widowmaker’s Grappling Hook to begin its cooldown after going through Symmetra’s Teleporter
[Console] Fixed a bug that allowed Mercy to receive Ultimate charge when using her Caduceus Staff to increase teammates’ damage when they’re not damaging enemies
[Console] Fixed a bug preventing Reinhardt from deactivating his Barrier Field after being hacked by Sombra
[Console] Fixed a bug preventing Sombra’s Hack from cancelling Soldier: 76’s Sprint ability
[Console] Sombra no longer receives credit toward her on-fire meter when her EMP ultimate hits Symmetra’s turrets
[Console] When multiple Sombras attempt to hack a health pack, the player that initialized the hack first will now control it
[Console] Fixed a bug preventing Sombra's Opportunist passive ability from seeing practice bots through the walls on the Practice Range
[Console] Fixed a bug preventing Sombra’s reticle from consistently expanding while firing her Machine Pistol

Maps

Fixed a bug that allowed Sombra to reach unintended locations on Watchpoint: Gibraltar
Fixed a bug that prevented Mercy from using Resurrect in rare situations on King’s Row