is attack on titan (shingeki no kyojin) episode 59 filler?

The military discusses the facts revealed in Grisha Jaeger's journals and the Military Police Regiment is largely against sharing their contents with the general population of the Walls. However, Dot Pyxis points out that doing so would make them the same as the previous Kings, ensuring that the population stays docile and ignorant.

Queen Historia Reiss decides that they will announce the truth, reasoning that they would simply be returning the memories that King Reiss had taken away. All of the people of the Walls will share the same fate, so she wants them to unite.