Middle-earth: Shadow of War will now launch worldwide on Oct. 10, 2017.
Monolith the developer of Shadow of War, wants to make it the best game it can be but unfortunately needs a little more time to work on it. With an apologetic post on their forums they broke the news of the delay. However they did say that there was more to show at E3 and to be excited for what they will reveal.
Source: WB Games community forums
You can reach me on Twitter @RicF