Running Location services with iOS 7sdk build on iOS 8.1 device

Apparently in iOS 8 SDK, requestAlwaysAuthorization (for background location) or requestWhenInUseAuthorization (location only when foreground) call on CLLocationManager is needed before starting location updates.

There also needs to be NSLocationAlwaysUsageDescription or NSLocationWhenInUseUsageDescription key in Info.plist with a message to be displayed in the prompt.

But if I build with iOS 7 sdk, do I need to make these changes for running location services on iOS 8 device? (I know how to run on iOS 8 device with iOS 7 sdk. Hack -I just need to keep the device plugged with xcode 6 also open and then I start xcode 5. It detected iOS 8 device on xcode 5.1)

Also Im checking for authorization status not denied before starting location updates which has same value in iOs 7 and ioS8. So can there be any reason for location services to stop working on iOS 8 when building with iOS 7 sdk.