Linked Scenes is just a normal scene with objects brought on from another scene. Like the way External Scene does but instead of needing to write code to CREATE and add the SCENE and all that, instead its just a normal scene.
This honestly would be more useful than Global Objects, since it properly allow you to wrote all game logic in say, a template/test level and use those objects directly in another scene to make other levels, while still being able to update the objects in the original scene and apply the changes to other scenes that are “linked”. See what I did there? XD anyways yeah.