I have a Missal published in 1949 which still has November 8 as “Octave-Day of All Saints.” It says “Mass as on the feast” (but the Collect, Secret, and Postcommunion are different).
If my memory serves me correctly, Octaves took two big hits in the 20th century, one under St. Pius X and one under Bl. John XXIII. That said, as we are dealing with a time prior to the standardization under St. Pius V, it would be difficult, and perhaps impossible, to ascertain the details of the calendar used in the French court.