Boeing offered the single angle-of-attack sensor as standard equipment, and charged extra for a second along with a “disagree” indicator that would allow 737 MA

Boeing offered the single angle-of-attack sensor as standard equipment, and charged extra for a second along with a “disagree” indicator that would allow 737 MAX pilots to “cross-check” a faulty sensor. Unfortunately for the author that's not an accurate representation of reality. I'm a bit surprised as I thought that EETimes was a credible news source.