No, conhost.exe is (since Vista, prior to that it was a part of csrss). cmd.exe is simply the default command-line shell. To disprove your guess here, you can just observe the processes existing when running console applications. There's one conhost for each console window, but unless you run cmd, there'll be no cmd instances.
Windows didn't have a terminal emulator until recently anyway, as Windows console applications use the console APIs to change cursor position, color, etc. instead of having that API as part of the text stream that's output by applications.