I think it should be. So tha you can animate its visibility. Currently I can only animate visibility/transparency using the Materials and set it to transparent, but even after the object has vanished completely from the view, it still casts shadows.
For a very simple fix you can simply enable ‘transparent’ shadows on all materials. Then, when you animate the visibility via the material properties it won’t cast a shadow when it is fully transparent.
For those that are looking for a easy solution to this, I’ve made a short Blender Tip video on how to easely achieve this with the new Blender 2.8 Principeled shader Node.