is attack on titan (shingeki no kyojin) episode 50 filler?

The Scout Regiment travels towards Wall Maria under the cover of night to begin their operation to reclaim the territory they lost five years ago. Along the way, they stumble across a Titan, but it appears to be asleep and does not react to their presence.

Hange Zoë speculates that it is not one of the new types that can move at night, but it could be inactive simply because they are traveling on a moonless night when the sun's light cannot reflect off the surface of the moon.