Devices from Apple that the user wears will likely never have hard edges. AirPods, Watch, Vision Pro, etc. They could take the Ultra design and make the body less bulbous but it would look like the many cheap fitness watches that have that design already because fully copying the Apple Watch design is too costly.
Much like how the AirPods have the iconic white stalks that will never go away, the shape of the Watch is iconic and instantly Apple Watch and anything else has already been done and ruined by poor quality and/or poor user experiences. Don’t need it instantly looking like a Fitbit instead, that would be disgusting.
With a “redesign” I’d like to see the displays be slightly larger in the same size case, True Tone on the display so faces can actually match their respective bands, and some new health sensors that have been rumored for a while, all while the body stays mostly the same rounded design and eight years of band compatibility isn’t abruptly ended. Maybe a smaller Ultra with 41mm band compatibility for folks who crave something different but smaller could exist.