Also noticed they are headlining Destiny 2 (from Activision+Bungie) in the Blizzard App store, and that it will be launched from the Blizzard App ("Blizzard Desktop app and registration required to play")
Activision and Blizzard are both owned by Activision Blizzard, so by putting Destiny 2 in Battle.net they can keep the share Valve would take for selling it on steam.