No, but it is a closed list and the public materials are, as you noted, apparently sanitized. What is the reasonable inference?
I have no idea. It just looks like bizarre crypticness to me; like there's some inside joke that I'm not in on.
If it is a closed list, then why is it being posted to LW? And especially, why is it being posted without acknowledgment of the fact that the source was a closed list?
Conspicuous secrecy is rude.
The fact that the list itself is closed is not a good argument by itself not to post the link given that the link is to a public and easily accessible website. However, it probably would have made sense of it had included the request not to the post to the blog.
Link.
Given the positive reactions, I think the professor seeded them with a positive impression of the site's content.