Wayback machine appears to have been removed as part of the publication of the book (guessing). https://news.ycombinator.com/item?id=4021548
The LOC has a different charter - its not trying to be "this is a copy of the full site at the time" but rather a historical documents around specific events ( https://www.loc.gov/web-archives/collections/ ) and has a different charter than the internet archive. https://www.loc.gov/programs/web-archiving/about-this-progra...