Give this a try:
"Export as catalog" the images in the non-date folders, click the checkbox to "include negative files".
Delete those images from the current catalog.
"Import from catalog" (the one you just exported), "use the import dialog", "copy" the files.
The "import from catalog" will preserve your edit history. Using "copy" should put the files into dated folders; confirm this in the Destination panel.
Obviously, you will want to test this using a small number of files first.
You could save the metadata for the edited images. Doing a CMD or CNTL S on any selected image will save the metadata to the hard drive. Then you could remove the folders from your catalog, and reimport them into dated folders. You will need to import them with the 'copy' method to do this. The new import will read the saved metadata. You'll probably want to delete the original folders after you make sure everything imported okay.
My advice is to not bother doing this.
If you need to find photos taken on a specific date, use the Filter Bar.
This is much simpler than re-importing with the idea of changing your folder structure, and there's no risk of getting things screwed up.