Miyamotoo on 15 August 2018
Expected after that Switch light hint from Blizzard.
Interesting fact, this will be first Blizzards game on Nintendo platform after 15 years, 20 if we don't count 3 SNES games released for GBA in 2002.
http://www.ign.com/articles/2002/12/11/blizzards-classic-arcade