Thank you for updating your support ticket and letting us know that you managed to resolve the issue. I will post your findings in this forum post so that the community can take advantage of them if they encounter the same issue:
We were attempting to publish the build using Apple Application Loader 3.0 which always results in this error: 'ERROR ITMS-9000: "Invalid Bundle. The bundle Cordova350.app does not support the minimum OS version specified in the Info.plist'
However, your mention of xCode made us realize there may be an older version of xCode on the Mac we were running App Loader 3.0 on. This turned out to be the case. So we installed Application Loader 3.0 on a different Mac system which does NOT have xCode installed on it, and it worked, we could send the build to iTunes Connect and submit the app.
So it would appear the older installation of xCode was affecting Application Loader 3.0 in some way, presumably they share some files. And that returned error message was entirely misleading. I would suggest a sticky forum post to state that IF you are going to use Application Loader to publish to iTunes connect then xCode must also be of the latest version IF it's installed on the same Mac system. If it's not installed then it doesn't appear to matter.