This spec is almost a copy of the existing APIs but with some additions, which in my experience they were very needed. The old APIs won't stop working. If you don't want several code paths use either the old APIs or pointer events with polyfill.
IMHO, the most important changes are pen support and the "touch-action" CSS property[1].
There have been many attempts to make native-looking HTML5 apps in phones and tablets. Do you know why none feel native? Scrolling. When you scroll, pan, zoom... JS events must fire and many things must happen before redrawing the screen. That's avoided with the "touch-action" property. There are other reasons but this has been the most important one.
[1] I would have preferred a HTML attribute, but things like "pointer-events" already exist.
IMHO, the most important changes are pen support and the "touch-action" CSS property[1].
There have been many attempts to make native-looking HTML5 apps in phones and tablets. Do you know why none feel native? Scrolling. When you scroll, pan, zoom... JS events must fire and many things must happen before redrawing the screen. That's avoided with the "touch-action" property. There are other reasons but this has been the most important one.
[1] I would have preferred a HTML attribute, but things like "pointer-events" already exist.