The first Blizzard game coming to Steam will be Overwatch 2, and it’ll be available on August 10th — just in time for Steamers (that’s what they’re called, right?) to participate in the Overwatch 2: Invasion event that introduces the long-awaited PvE story missions.
I wouldn’t be surprised if this had something to do with the impending Microsoft buyout, seeing as they’ve been putting all their PC games on Steam for a while. That being said, I also wouldn’t be surprised if Microsoft starts moving away from both Steam and Battle.net once the deal closes in favor of the Xbox launcher now that they have a ton of potential exclusives for it.
I’d say it’s more a continuation of how Activision put COD back on steam when they tried to keep it on their platform for a few releases.