Apple docs have references to eg: "macOS 10.8+" regarding SDK version. This may still be up in the air, but I predict it will be natural eventually to just use macOS everywhere.
Wow really? I've never seen that in user facing information (eg they kept using "Mac OS X" for older versions when they dropped the "Mac" a few years ago
I was referring to technical developer documentation, but I don't think user facing info will be that much revealing until after 10.12 is released.
I say that I predict using macOS will be "natural", although that doesn't necessarily mean it'll be "technically correct" for older versions.