Hmm, it seems we got some wires crossed after all.
What we used to upload successfully to apple was
- All the iOS launch images set in the game.project
- DTPlatformVersion set to 8.0 in Info.plist
<key>DTPlatformVersion</key>
<string>8.0</string>
It seems that we missed correcting the platform version before the release.
Please let us know if this works for you!