I found this good article about how to log out another user without logging in on macOS..
However, I haven't been able to find any information online about restricting the simultaneous login session on macOS to just 1, which is similar to Windows desktop RDP session (licensing restriction).
That way even though concurrent session can still be established but only one active login session is allowed remotely at a time just like console user session through fast user switching. Yes, the new user login will disconnect the previous user session but at least the application status and data are all still preserved for the previous user because his/her session is not logged off. This may also help encourage users to simply jump onto another machine in a lab environment when finding the current one is already occupied just like the prompt on Windows machine: "Another user is signed in. If you continue, they’ll be disconnected. Do you want to sign in anyway?"
Is this possible?