Lacking a home button it would make sense that this feature lost with iOS 10 might return with the new iPhone - one very little thing I'd be quite pleased to see as STU was probably one of the iconic iOS 'things' through the years 
While we're at it I guess I'll also ask what other gestures people think might be brought in to unlock (just raise it up to your face?) if it's not STU.
While we're at it I guess I'll also ask what other gestures people think might be brought in to unlock (just raise it up to your face?) if it's not STU.