We've always only supported the currently released iOS, and the previous iOS release because of test device OS constraints. Currently our support is for iOS 10 and iOS 9. iOS 9+10 support is at 92% of users according to Apple: https://developer.apple.com/support/app-store/
Coinciding with the drop of node 0.x support (see http://cordova.apache.org/news/2016/10/01/0.x-4.x-deprecation-timeline.html) which we are bumping a major version of the platform for, we will drop iOS 8 support at the same time. The timeframe for cordova-ios@5.0 release containing these two changes (among others) is Jan 2017.
