"These ribs are made from halved or butterflied rib chops from the blade (shoulder) end of the tenderloin. They contain both dark meat from the shoulder and light meat from the loin."
In a perfect world, yes, but not common in my neck of the woods. What I usually find are "Pork Shoulder Country-Style Ribs," which are, indeed, a band saw-sliced Boston butt. I have seen every piece of the blade bone from the butt in the package. I also asked the meat cutter at my local grocery store about it, and he confirmed that it was a sectioned Boston butt.
I think to be technically-correct, butchers are supposed to label the country ribs you referred to as "pork loin country-style," but not certain. From what I've read, as country-style ribs became more popular, butchers pushed farther into the shoulder because the meat texture was similar.
So, depending on your neck of the woods, folks can get either/or, and while similar, you are right that they are not the same. Good catch, Kari!