Those big squatters only use their hips and lower back to move that much weight. They're essentially doing good mornings which leaves them with stick legs and huge asses with wide hips.
Still there's a big loss in size, even though he still squats heavy or did very recently. "Powerlifter squats" perhaps don't bias the quads very well but they are good enough to build leg size, or maintain leg size. But something happened, maybe some injury.
He used to have "big" quads.