Yeah, I've noticed this - I made a funny little art project in 2013 wordclouding parodies of This is Just to Say (and later other famous poems and literary quotes that often get parodied) because wordclouding is the least interesting kind of visualization there is:
and quite a lot of the content I used is no longer found, so all that remains is the word cloud but not the original poem.
It's a bit worse than the article details though because often the web page is there, or if not is available from IA, but much of the content was actually inside of comments and so forth.
(project was originally inspired because back then you couldn't go anywhere on the web without someone hitting you over the head with their This is Just to Say parodies)
https://medium.com/luminasticity/fruit-stealing-scoundrel-ha...
and quite a lot of the content I used is no longer found, so all that remains is the word cloud but not the original poem.
It's a bit worse than the article details though because often the web page is there, or if not is available from IA, but much of the content was actually inside of comments and so forth.
(project was originally inspired because back then you couldn't go anywhere on the web without someone hitting you over the head with their This is Just to Say parodies)