It won't be back. It's not Arnold or MacArthur.
Apple’s BIG Plans For 2017’s iPhone 8 Revealed: ALL-GLASS Design, New OLED Display Tech & IRIS Scanner
http://www.knowyourmobile.com/apple/apple-iphone-7s/23205/iphone-8-release-date-rumours-specs-features-detailed-2017
and....the headphone jack is coming back due to popular demand!