Activision killed Blizzard already. They've already started to actively fire Blizzard execs. Activision in the past would leave Blizzard alone, recently though they've taken over final say on creative decisions. All of their games have turned into either loot box jerk off bullshit or mouse on the wheel stringing people along to keep them logging in. It backfired hard though and Blizzard games are purging players.
Unfortunately Blizzard can't just leave like Bungie did, Activision owns more of Blizzard's stock than Blizzard does because of that sneaky ass deal in 2008 that forced Blizzard under Activision under their nose.