I know essentially nothing about any of these tools, but I get the impression that the report is arguing that the API for ML is really up at the Python layer, a

I know essentially nothing about any of these tools, but I get the impression that the report is arguing that the API for ML is really up at the Python layer, and ML programmers don't interact directly with the stuff you're talking about. If the new PyTorch funnels everything through abstractions that don't require you to implement as many primitives to port it onto a new backend, then it matters less than before if ROCm (or whatever...) is harder to use, because the person doing the port don't have to do as much with it, and the actual application programmer never sees it at all.