DZ,
The Kadet conversion kit that fits on to a cz-75 frame uses a fixed rib to mount the sights on. The moving part of the slide is under this rib. From what little I can see of the photo in your link, the new pistol simply improves on the Kadet design a bit.
This is, of course, just one example. Other .22s place their sights on non-moving parts also to increase accuracy. The Ruger Mark II is like this.
Joe/Ga