Christopher Judge, the voice of Kratos in the God of War franchise, previously listed on his Twitter account that God of War 4 was intended to release in 2017 shortly after the E3 2016 reveal trailer. Now it seems that the game might have secretly been delayed as he now lists the game for a 2018 release.
Some even reached out to God of War Director Cory Barlog to ask him and Cory stated on Twitter
“nothing wrong, games are just very big, very complicated, require constant collaboration with lots of different experts. not2worry”
Expect an official release date to be announced at E3 2017.