They often discard with the version number for the first release of a product bifurcating, and from then on it follows its own version path.
The first Apple Watch Ultra wasn't the Apple Watch Series 8 Ultra. Subsequent Ultras follow their own versioning. The same with the SE, Air Pod Pros, iPad Air, and so on.
Yet that's precisely what Apple has done repeatedly across product lines. Just yesterday they introduced the Apple Watch Series 11, and its low cost variant the Apple Watch SE 3. They also introduced the ruggedized larger variant the Ultra 3.
