Update 3rd party plugin?

I’m aware of this post here:
but I’d quite like this clarified. Is there a way to update a third party plugin in Unreal? Specifically the ARKIt plugin?

Presumably, the plugins all get shipped with the latest version of the Unreal engine?

The reason for this is that I’ve had some (conflicting) advice about updating plugins from Apple after a rejected app for Unity - You know Unity, Unreal. Tomato, Potato - They’re the same right?!