Anyone's iOS device is essentially "mirrored" if using iCloud backup.
If for some reason an individual's personal device so happened to have content with NAT SEC sensitive data on it (due to dumb email hiding, or taking selfies in dumb places that may have geotagged metadata) then that's that. Game over…
Apple will comply with subpoenas that are written correctly, to get ALL the data we need. Retrieval of data doesn't require hacking devices when it's all in iCloud.