One of the best new features in iOS 10 is the ability to delete all of those stock bloatware apps that you never use. Instead of hiding them in a folder somewhere to get them out of your way, you can finally remove them—or at least, that's what we wanted to believe.
As it turns out, you're not actually "removing" these stock apps. Instead, they're just being hidden from your home screen and Settings menu, or just temporarily disabled. To prove this fact, we recorded a little demo video, and what happens here wouldn't be possible if the apps were truly removed.
To give you a bit of background, stock apps that have been removed in iOS 10 can be re-downloaded from the App Store. But that shouldn't work with Airplane Mode enabled (as it was in the video), because you can't download anything without an internet connection.
As you can see, however, the removed app "downloads" just fine in Airplane Mode. This indicates that the app was never removed or deleted in the first place, and instead, was simply hidden from the home screen or temporarily disabled at a system level.
It's a minor gripe, because we're still basically getting what we've always wanted, in the sense that we can finally remove those unwanted icons from our home screens. But it's something that could use more clarification, since it could make a difference in terms of storage. Maybe that's why they didn't mention it in their WWDC keynote.