There must be a misunderstanding here, You don’t want to see “Raytracing” Building lighting, that would be incredibly limited to the usual realtime raytrace method which includes only a single bounce per light and other million artifacts.
What you want to see instead is GPU rendering assisting the CPU, similar to offline GPU renderers, like Vray GPU, and it would be better to use both CPU and GPU to bake lights since it would be incredibly limiting again to just use the GPUs.
GPU rendering is what is mentioned in that screen grab not “Raytrace” this is the same concept as the lightbaker in Unity right now.