We are writing an iPad-only app (i.e. not a Universal app), and are setting "QMAKE_IOS_TARGETED_DEVICE_FAMILY = 2" accordingly in our .pro file.
This should end up getting translated into a "TARGETED_DEVICE_FAMILY = 2;" entry in our Xcode "project.pbxproj" file. Until recently, this worked, but with Qt 5.8.0 and Xcode 8.3.2, we end up with "TARGETED_DEVICE_FAMILY = 1,2;" in that file--which indicates a Universal app supporting iPhone and iPad.
As a result, Apple has rejected our most-recent App Store update submission (since we don't include iPhone assets, for obvious reasons).