We need actual proof.

According to the Chicago Tribune, the episode ''The Great San Francisco Earthquake'' was re-aired on October 24 instead of the previously scheduled ''The Great War-1918." Then it becomes complicated:

the producers [...] also told me that ''The Great War'' was being held for future airing, that the next edition of the series would be ''Wildcatter: A Story of Texas Oil'' and that other PBS affiliates had decided to follow suit. WTTW-Ch. 11, however, opted to go ahead and air ''The Great War-1918,'' holding ''Wildcatter'' for a future date.