Not a single one of those requests contain the string "This is a message site. I guess. Just checking.", or did I miss something? All it seems to load is the "website loader", which is the part that decodes the URL (locally) and displays you "the website".
So assuming you have local access to the loader and you have the parts from the URL, you'd be able to load it.
I'm not sure if y'all are consciously misreading how this is supposed to work, or if I'm misunderstanding what y'all are complaining about. It's not "A public internet website can be loaded if you're not connected to the public internet", it's "websites loaded in this way can be loaded this way as long as you have the loader".
It is very much not, open the network tab on any of the examples, behold.