Re-inserting the link does not work, even in the text editor. Even if it worked, I certainly don’t want to do that for the +100 videos I have on the blog.
When I deactivate all plugins, it’s the same, no video.
Videos may be handled by WP as you say, but when I have all the plugins activated and Contango Free, all videos show.
When I have Twenty Twelve, all videos show…
When I have Contango Pro, no videos.
So, what is it?
See the screenshots included for Contango Free and Twenty Twelve.