I think that by now we shouldn’t take a .0 major release as a sign of what is really going to be present in macOS and what’s not. The OS stabilizes around .4 or so, and in the meantime some deprecated things may get removed, too.
They also have a habit of sometimes add or change some APIs mid-cycle, so you may see requirements for the latest Xcode being a mid-cycle version of the OS. Or how was it with Mac App Store, that not only itself, but the relevant APIs for programs distributed in it appeared in 10.6.4?
They also have a habit of sometimes add or change some APIs mid-cycle, so you may see requirements for the latest Xcode being a mid-cycle version of the OS. Or how was it with Mac App Store, that not only itself, but the relevant APIs for programs distributed in it appeared in 10.6.4?