I'm pretty sure iPad Pro doesn't have 3D touch mechanism but after I updated my device to the latest iOS 11 beta 3 some of the new updates include 3D Touch.
See picture below
That kinda leads me to think if it's really the 3D processor that they put on the new iPhone and iPad that made the device work on 3D touch or it's just a code trick wherein they just calculate the time you hold or press the screen and it will show the popup menu. I'm not sure if this trick works too in iPhone I guess I will just find out after I updated my iPhone 6 which doesn't have 3D touch mechanism too.
What do you think about this?