Oh my this is fantastic! This is important work for archiving, honestly. I can't seem to find "3C4-OCR-WMF - THE MYSTERIOUS MANSION" though. The others do appear to be backed up, which is just so important, honestly.
I don't know how possible it would be, but I think that it would be potentially really nice to have all the officially endorsed or highlighted SMM2 levels backed up for archival purposes. The full list can be found on the Mario Wiki under the article "List of fan-made Super Mario Maker 2 courses...