The 2017 release date was announced for the sequel shortly after World War Z hit theaters in 2013.
There was simply no way World War Z 2 was ever going to meet its summer 2017 release date.
The Hollywood Reporter doesn’t give a definite reason for this halt in production on World War Z 2.
The original World War Z movie, which was based on Max Brooks zombie survival guide of the same name, was faced with quite a few problems of its own during production.