This feels suspiciously like the goals of Microsoft's "Metro" design from the Windows 8 era. It will be interesting to see if Apple can do a better job of keeping the same design without damaging the desktop experience than Microsoft did.
As for the second part, Apple does a remarkable job at updating all of the OS to a new design language. Unlike Windows, which last time I used it, had three different settings panels and UI controls resembling archaeological layers going back to pre XP.