It’s basic United States separation of powers. If Congress passed a law eliminating or banning non-completes, then it would be legal.
As an asdie, it seems that the Biden administration is positioning itself to overstep it’s authority with things it feels would be popular with specific voting blocks that will obviously be overturned by the courts and then position that the courts are too partisan. They are satisfied with how this works with voters even if the actual policies cannot actually be implmemented.
I don’t think most serious observers felt this would make it through court review.