I don't see why Sound Wave would have any advantage, even efficiency, over a similar Zen 5/6 design. Microsoft must really want ARM if they're having this chip made.
They did countless attempts to use ARM but all failed. Consumers didn't care because they couldn't run their software. Microsoft won't solve the problem until they will provide a way to run all relevant software on ARM.
A year or two ago I used a Windows 11 laptop with an ARM CPU, and at least for me everything just worked. The drivers weren't as good, but all my x86-64 software ran just fine
Its pretty decent. Decent enough in fact that I can run a Windows 11 ARM install on vmware Fusion on my macbook m4 pro, and it will happily run win arm and x86 binaries (via builtin MS x86 emulation) decently fast and without complaint (we're talking apps, gaming I haven't tried.)