The following information has been given in the latest patch notes from Blizzard:
Two new game modes have been added to the Arcade: Deathmatch and Team Deathmatch!
In Deathmatch, eight players go head-to-head until one player scores 20 points. Players will earn 1 point whenever they land the final blow on an opponent and will lose 1 point whenever they die to environmental damage (ex: falling off a cliff) or self-inflicted damage. This scoring will be tracked in a brand-new scoreboard. The first player to 20 points wins!
In Team Deathmatch, two teams of four players face off until one team scores 30 points. Players will earn 1 point for their team whenever they land the final blow on an opponent and will lose 1 point for their team whenever they die to environmental damage (ex: falling off a cliff) or self-inflicted damage. If players are resurrected before they respawn, the corresponding point for their death will be deducted from the enemy team’s score. This scoring will be tracked in our default scoreboard. The first team to 30 points wins!
There is also a new map, called Château Guillard.
Château Guillard is located near Annecy in southeastern France. For hundreds of years, it was the estate of the influential Guillard family, until it gradually fell into disrepair after the family’s power waned in the decades after the Revolution. Recently, the château has found a new owner: the Talon agent Widowmaker, who has returned to her family’s ancestral home.