The little "m" works for me because it's consistent with the other naming conventions. Sure, it looks weird today, but we'll eventually get used to it. It's like when they changed the name from Mac OS X to just OS X. At least the word "mac" is back in the name now.
I never got used to OS X.
I typically will refer to OS X as OS X unless the version was still called Mac OS X (e.g. Tiger, Snow Leo, ...), but I never got used to it.
It sounds so undefined. Like calling a car "Car 2" or something.
When talking to non-techies I will usually just say "the Mac operating system" (operating system in my language though) or just "Mac OS X".
As soon as I say Mac, even non-techies know what the **** I'm actually vaguely talking about.
Because, you know... Apple doesn't really run a lot of Mac ads here in Germany, so for the non-techie, the term "OS X" is meaningless most of the time.
Great naming decision back then, oh well...
As I see it there are two major posibilities about this.
1. Someone in PR or something, just mistypes it for whatever reason.
2. They are actually going to change the name soon.
My money is on the first.
I have a hard time believing that this is just a slip-up.
This looks a lot like testing the waters for the name/getting everyone used to the thought of a "macOS" so that any reservations that may be temporary are gone by the time the change is officially announced.
You'd be surprised how staged everything at Apple is.
Glassed Silver:mac