Not to pile on, put the notion put forward in the quote below seems very odd to me, so much so that I wonder if it is accurate.
"When you select the option to use iCloud Drive for Desktop & Documents, that is exactly what it does - it removes them from the local drive and puts them on iCloud Drive. Since you cancelled the process in the middle, the folders had already been removed from the local drive, but had not yet finished uploading to iCloud Drive."
Apple is reasonable, usually, so I imagine there would not be a time when your files were NOT on one or the other, i.e. your drive or the iCloud Drive. GFM suggests there is a point at which the data is swirling around untethered in the ether! I wish we had some formal clarification of this issue.
Also, as a side note, I have found that while the folks here try their best to help others, often things end up in a kind of counter productive wrangle. In these cases I usually move on to other more objective forums such as MacRumors or MacObserver and similar. Doing so also lightens the load on the dozen or so folks here who do the bulk of the replying to especially new user questions.