In the SceneView.h header file, there’s an FSceneView class that contains a bCameraMotionBlur boolean.
class ENGINE_API FSceneView
{
public:
...
/** Whether to enable motion blur caused by camera movements */
TOptional<bool> bCameraMotionBlur;
It does appear to be used by a few motion blur related classes, however it doesn’t appear to be something exposed in the nDisplay plugin, and not something available by default to engine users.