I don't believe they've proven class A. Just because you have a device that computes something and that devices has entanglement does not mean you've exploits

I don't believe they've proven class A. Just because you have a device that computes something and that devices has entanglement does not mean you've exploits the entanglement to compute anything in any useful sense. An extreme example: you can prepare a superposition and measure it to generate a random classical bit (0 or 1), and you can use that as a source of entropy for a classical probabilistic algorithm, but it would be ridiculous to call this a "quantum computer" of any class. In fact, multiple experimental groups did essentially this, which some theorists at IBM (former colleagues of mine) called them out for: https://www.nature.com/nature/journal/v499/n7457/full/nature12290.html https://www.nature.com/nature/journal/v499/n7457/full/nature... Although this case was egregious, more subtle shenanigans are rampant in the field.