Found: it's a sentence from 2020, and PG decided not to appeal (!?)
Full story (in Italian) at https://www.wired.it/internet/web/2020/06/30/progetto-gutenb...
It looks like the issue was that, in Italy, copyright expires 70 years after the death of the author or the first translator of a work.
Seems like a case for HTTP 451 (Unavailable for Legal Reasons) rather than 404.