https://www.gamespot.com/articles/overwatch-teaser-could-point-to-a-new-hero/1100-6456959/

Blizzard today released a cryptic teaser for Overwatch that some believe could be in reference to a new hero named "Emre Sarioglu." The teaser takes the form of a declassified After-Action report for something called "Operation White Dome."

As explained in the text below, Operation White Dome took place on the outskirts of Istanbul, Turkey and involved captain Ana Amari (a current Overwatch character) being deployed to "deal with a remaining pocket of omnic resistance." Also on this excursion were Overwatch characters Reinhardt, Torbjorn, and "Private First Class Emre Sariogulu." That last name is the most notable one, it seems, as it could be a new Overwatch character.