Afaik, they don't actually "purge" the history, merely hide it. If the robots.txt is updated again at any point, all the history pops back. Hiding information r

Afaik, they don't actually "purge" the history, merely hide it. If the robots.txt is updated again at any point, all the history pops back. Hiding information requires active maintenance, which is a very clever way of making as much as possible available while avoiding liability.