Diablo 3's art style is an odd one though, focused on almost oil painted backgrounds with more realistic models in the middle of it all, it reminds me of some animated movies. Im not sure if ray tracing would work well with it but it would be fun to see more games with it.
Most animated movies made in the last 2 decades have used ray tracing in some way, in fact animation studios have been using ray tracing and path tracing for about as long as VFX companies.