I am experiencing the same issue.
Apparently the situation is impossible:
The problem here is:
- To pass the Facebook Review process you need to send them your App in one of this two available format, 1) the Apple App Store App (that is impossible to do, you can not send App Store an unfinished app), or 2) a Simulated Build (using Terminal to build the project in xcodebuild -arch i386 simulatorXX). None of this available options provided by Facebook are posible technically, so it's technically imposible to obtain the approval of the App. This is because:
1- App Store is not going to pass an App that is not working (the FB butto won't work, so App Store is not going to allow us finish the process and they will reject). so at the you can not provide an AppStore-id to the Facebook Review team.
2- As far as Facebook only receives "Simulated Builds" it would be impossible to a Vuforia Unity App to be accepted, this is because when you are using Unity + Vuforia you can not build a simulated build, is incompatible. So is impossible to fit this requirement.
Only workaround available I can think of would be to:
1- Send the app to apple store, remotely disabling the Facebook functionality.
2- Once is approved by Apple, remotely enable the Facebook functionality and sending the app - THE APP STORE ID - to Facebook Review.
Otherwise, Facebook should open another via to Vuforia-Unity developer to review their IOS apps.
This seem to be the only way for Vuforia + Unity, but I didn't check it.