RemoteViewPitch is replicated in a byte (0-255) to save on replication bandwidth (though this is less of a concern these days). This code looks like it says for non-local characters, you need to set the rotation of the camera, and you do that by remapping the byte to a 360 degree value. Reorder the statement to ((float)RemoteViewPitch / 255.f) * 360.f and it might make more sense. Map to (0…1), then scale to (0…360).
See APawn::GetBaseAimRotation() and APawn::SetRemoteViewPitch().