The Luminous Studio head mentioned this in his presentation regarding the demo. But yeah all of the direct lighting, GI, AO, shadows, reflections are path-traced.
"In addition, the scene contains many translucent objects, including hair and eyelashes. When a ray hits a polygon that makes up such a semi-transparent object, it is necessary to read the texture and test whether it is opaque or semi-transparent every time.
Nonetheless, if everything is drawn with ray tracing, it can't be moved in real time, so there are a number of compromises. For example, in the case of skin expression, a subcutaneous scattering simulation that throws countless rays under the skin is not performed, and the same processing as the simple subsurface scattering technique "Screen Space Subsurface Scattering", which is often used in recent game graphics, is used as a proxy."
They started developing the demo back in June. The first version they developed only ran at 5fps.
Also, regarding next-gen consoles:
"Since the Back Stage demo has been developed as a demo that runs on Windows, in order to implement real-time ray tracing, it is necessary to install "DirectX Raytracing" (hereinafter DXR), a real-time ray tracing framework for Windows 10.
However, Luminous Productions must also consider compatibility with stationary game machines other than Windows PCs. Moreover, the next-generation Playstation and the next-generation Xbox " Project Scarlett" have been predicted to support ray tracing.
As with the current Xbox One series, the next-generation PlayStation is expected to adopt its own real-time ray tracing framework, apart from Project Scarlett, which is sure to be based on Windows x DirectX.
Therefore, Aramaki says that Luminous Engine has intentionally abstracted the functional blocks that perform ray-tracing processing without using DXR-only specifications. In other words, the Luminous Engine side defines the API and functions for ray tracing processing and controls the DXR from here. Now, for example, in order to support the next generation PlayStation, the same graphics can be drawn just by replacing the abstraction layer."