This is an important clarification; from the abstract and title I was super confused how they identified a "subspace" that could be consistently identified across model structures (I was assuming they meant that they saw stability in the dimension of the weight subspace or something), but if they're just referring to one model class that clears things up substantially. It's definitely also a much weaker result IMO, basically just confirming that the model's loss function has a well-posed minima, which...duh? I mean I guess I'm glad someone checked that, but called it "the universal weight subspace hypothesis" seems a bit dramatic.