It very much sounds like marketing hype to repeat this "direct to assembly" thing so much. Essentially it's claiming they are better at writing optimizers that are the more numerous authors of GCC, LLVM, etc. That's not inconceivable, but it's a hold claim requiring strong evidence.
Thanks, Antoine, for pointing me in right direction about PyPy. I knew they experimented with LLVM, but thought that avenue was more of a success. Indeed PyPy directly generates it's machine code, so maybe that approach is a good one. But PyPy also had a decade or more of effort behind it to get as good as it is (and it's open source)