i saw your message yesterday and i notice many others did too. and none of use chose to answer.
i'm not sure why the others failed to answer but i did not because i wasn't certain i am correct and thought someone who's done this before would be able to answer with more certainty.
but in view of no one answering i thought i would respond today: i believe you're incorrect, the local files will be used to update your cc files. ie, you'll lose your cc files and end up with the desktop files only, exactly what you do NOT want.
to work around that, in your cc web folder create a new "share" folder. move select all your previous folders/files to that new folder. share the new folder with yourself and download that folder that contains all cc folders/files.
you can then copy (don't move) the downloaded local share folder to your local cc sync folder and resync. once your satisfied all is secure you can delete the local share folder that you copied to your sync folder. (though if you're not pressed for storage, imo it's a good idea to maintain a copy of important files that not dependent of cloud stoarge acting sensibly/reliably.)