This one’s not quite black and white
We’ve been able to do remote screen sharing since forever on macs. First there was Timbuktu (who remembers that) which crazily was useful over a modem (who remembers those). Then there was the free VNC which I used frequently to support clients. So if it’s just down to screen sharing then there’s a hell of a lot of prior art going on.
However I think that the sticking point here is that on a Mac with multiple user accounts it’s possible to remote into any of those accounts, and this remoting in will work for multiple users simultaneously. I remember being on a Mac OS X server course, back when it needed a bit more than an average chimpanzee to configure, and one of the questions raised was if we could use a single Mac with multiple accounts like a Citrix server. The course leader looked into this and asked Apple directly.
The response was that while it’s possible to do this it would be in violation of the EULA, which only allows such access for system maintanance and support, and not as a working desktop. This is something that I cannot independently confirm, however as the course leader was Apple accredited and had lines into Apple I’ve no reason to disbelieve him
From my extensive experience in the Apple world I do not know of any company utilising ths facility in any way other than support. And then the support workers will be 9999 out of 10000 times logging into an already active desktop to support the user, and then the chances are that Teamviewer will be used rather than the inbuilt remote access.
It’ll be interesting to see where this goes.