Okay, so some are pointing to this new mysterious post as something to do with the next Overwatch hero. But, this time last year we got similarly cryptic
clues referencing a specific Overwatch mission. Which led to the excellent story-based Uprising event. So with that in mind there's good reason to believe that Operation White Dome will be a similar story-based co-op event.
Here's the initial tweet.
And the more recent post
, which mentions "a routine Overwatch mission that went off the rails when the team was ambushed by omnics, resulting in Reinhardt coming to the rescue of a severely injured Torbjörn".
Now that, sounds like the basis for some cool new story content. Of course we could be wrong and this is all in reference to the next hero, named Emre Sarioglu.