Something with the header 'Overwatch Mission Archives' that will unlock, or become declassified on April 12. What could it be? Well, your guess is as good as ours. The word mission implies some form of story-based content, and the 'King's Row Uprising' tag listing it as an event from 7 years ago within the Overwatch universe lends itself to something along the lines of a new mode. Maybe. Again, we're not sure what to think.
Here's the teaser.
It could even be a new event of some sort, but whatever it is our hopes are riding high on some form of co-op mission set in King's Row. That would be sweet.