That there is a maps folder in the content browser and that maps are created solely as the province of the editor; the fact that the map objects don’t appear in the editor is pretty much broken functionality. At the very least I’d file this as a bug that needs to be resolved because it’s horrible workflow.
Maps should appear in the content browser in the folder that’s created for them by default. Double clicking a map should open it in the editor (the same as opening it from the file menu.)