SceneManager.sceneLoaded returns scene.isLoaded as false, is this intended?

i'm adding a delegate to Scenemanager.sceneLoaded and try to load a scene, whoch works fine so far.

 SceneManager.sceneLoaded += OnSceneLoaded;
 SceneManager.LoadSceneAsync(name, LoadSceneMode.Additive);

but if i want to do something with the scene in the callback function, for example

 void OnSceneLoaded(Scene scene, LoadSceneMode mode)
 {
      Debug.Log(scene.GetRootGameObjects().Length);
 }

it will throw an exception "ArgumentException: The scene is not loaded.".
scene.isLoaded is in fact false at this point, as it gets set to true in the next frame i assume?

is this intended behaviour of the scene? i'd really like to do stuff with the scene when its loaded, it seems useless to have a sceneLoaded event when the scene is not marked as loaded.