Initially was just a test, but I think now should be moved to bug reports ;)
I edited the first post of this topic adding the link to the playlist. If you copy and paste the link into browser the playlists shows correctly, but if you paste it into a post there is no way to see correctly the link.
There's always a link on top. :)
There is also a protection against auto-embed built into the script.
Same line: https://www.youtube.com/playlist?list=PL-72lYkqnSfXj7LaTlGfsLhYoNO2xjKkc
Edit: anyway, I suppose if we change the last regex to something like this:
(?:\/)([\w-]{11})
Yep, I forgot about this little trick. Problem solved ;)