that benchmark was pretty much strictly CPU. but yeah, consoles are supposed to already have very low level api's. but I think dx12 will make it easier to efficiently use multi coresConsoles don't have an nvidia chip inside, nor do they have a discrete graphics card in there either ;)
It will be interesting to see, but I will be very surprised if it has a big impact on the xbox one. I am sure some developers will continue to find ways to squeeze the most out of the hardware, but that's usually a result of teams working on the system for years and finding ways around the bottlenecks.