Regarding the insane changes to itunesconnect.
When you successfully upload a build from Xcode,
I had the same issue and now I have solved.
The reason for that is that your build is missing something that apple servers is unable to determine.
to solve this, make sure you have included all possible settings needed for your app submission, and make sure you have added at least one of the launch images for every possible resolution, that was my case, I added an launch image for every device and did works.
so, carefully check if you project is missing one of those settings or an image, and try. thanks