SceneWorld vs. Scene?

Resorting back to forums because I can't seem to get an answer anywhere else:

What is SceneWorld/SceneObject vs. Scene/GameObject? - What are/was the intended purposes for SceneWorld/SceneObject? If they are being depreciated, how are they going to be replaced?

I'm currently using a custom Skybox due to hardcoded file names - it relies on a SceneCubeMap which derives from a SceneLight which is a type of SceneObject - how am I supposed to be using these, if at all? What alternatives should I be using in place of any SceneX related classes?

I can't find any documentation outlining the differences or use cases between the two so I am cautious as to what I should be using and where. We were told SceneWorld/SceneObject is going to no longer be used in future - so how is that all going to be handled? Even things like lights all rely on SceneLight at some point in their inheritance - are they all changing in future or are SceneObjects etc. just going to be locked away from general development?

I want to make an educated-as-possible decision on how I'm going to handle making what I am, but when I look through engine code for examples to build off of there appears (to me anyway) a significant amount of classes and engine functionality that rely on these things.

SceneWorld and SceneObject are what the internals of the engine use to represent render objects.

Okay, so for example a cubemap - there is SceneCubemap which is internal and EnvmapProbe which is what we should be using/inheriting from? 

In my case, am I safe to make a custom Skybox using a SceneSkybox, given that Skybox2D is where my issues are?

No you shouldn't be using them - if you ever use them then there's some functionality of the GameObject/Component system missing and we need to fix it.

Thanks, I'll try and make do with what is available as GameObject/Components and make issues if I find I need more functionality.