I think the author of the article is willing to accept that, and it's part of his point. The point is not to label languages, but to illuminate how we ended up with our current combination of software and hardware design. He points out that we are in a local-maximum with respect to processor performance because most of the optimizations we've made in processor design the past few decades break the C abstract machine. That requires the compiler and processor to go through awkward contortions to present the fiction of that abstract machine while still getting good performance. The final section, "Imagining a Non-C Processor", is where he explores this idea.
Take a look at maxas [0], and the maxwell/pascal microarchitecture if you want a modern example of low-level language (iirc. they are still manufactured on small mainstream process nodes).
Or maybe we should relax the definition of "low-level language" a bit?