The map was announced during BlizzCon 2017 before the 2017 World Cup on November 3rd. It was released on the PTR shortly after, with an official release planned for the "beginning of 2018".
Top-Down View of the Map
Image courtesy of Statbanana: https://statbanana.com/images
2017-11-03 | [COMING SOON] Blizzard World | New Hybrid Map | Overwatch by Blizzard Entertainment