Thanks!
I just used Windows File Explorer to copy my directory structure and files from the old to new NAS. (I was leery about this given that Adobe Lightroom gets wanky moving files outside of Lightroom itself.)
I then tried the suggested "Update database to point to new location (no file rename, move, or copy) ", but this did go as planned, as with my hierarchical file structure, music\genre\artist\album\track, it pointed to the base directory only, e.g. music, not the complete structure, and therefore the files are NOT there.
But this seems to have been easily corrected by re-pointing my auto-import to the new root directories, e.g. NASnew\music\ and NASnew\video\, performing the import, and then going NASnew\music\ and NASnew\video\ root directories and selecting/deleting all the files in the base root (no files actually there).
Afterwards, MC only sees the actual files in their correct directories.
It is amazing how fast MC23 is at finding the files!