Here the canonical url of this post.
Here is the "main" url of this post.
And here is the draft url of this post (which by the way kept the first version).
Main posts don't look affected.
I discovered it by clicking through the link available through the list of my posts and comments. It uses the "main" link even though the post were submitted on the discussion section. The visible consequence is if I use the "main" link, my post looks like it has been submitted to the top level.
I haven't tested whether this can hijack the karma system.