If you want to post a YouTube video marked "Embedding disabled by request", then do this:
1. Create a playlist with the video(s)
2. Make a "custom player" for that playlist, which provides its own embed code.

You can then embed your custom player on VideoSift!

I suppose they will eventually find that bug, but who knows. I just now got this to work for my post that had died: http://www.videosift.com/video/King-Crimson-Easy-Money-live-1973