How to auto refresh VLC media library?
Solution 1:
Don't have a perfect answer for this problem but probably the best solution at the moment is to go to %AppData%\Roaming\vlc\vlcrc. Then open vlrc with a decent text editor like notepad++ and hit control+F and search recursive.
Change from #recursive=collapse to recursive=expands and hit control+S to save. Then reopen VLC and in media library add the top folder or folders (music,video,podcast,etc) to the media library. These folders should be blue and when you double click on them they turn gray and will begin listing their child folders and files automatically.
You'll still need to update the playlist manually but now you can let VLC do all the work for you by simply adding the top folder again and double clicking on it. It will then give you an updated playlist and then you can simply "remove from playlist" the old version of the top folder.
Obviously this still isn't ideal but I suspect this updating could be made automatic each time VLC loads through a plugin and I wouldn't be surprised if such a plugin already exists.
See Automatically Expanding Media Library Folders.