I have to ask what is probably a dumb question.
Why? I used CodeMirror on three projects. It was great. Now I use Monaco aka Visual Studio Code. What would CodeMirror offer ? With Monaco I get all the lastest feature of VSCode . Current versions of Monaco include Intellisense etc..
I'm honestly curious both what CodeMirror will offer and why even try to compete. Though I'm guessing the answer to the first question answers the second