If Dave Arnold says he really doubts it, it's a pretty safe bet he's read like a dozen papers related to the prediction and is basing it on something. He's like the Bunnie Huang of cooking.
FWIW, some beans are easier on my system than others. Kidney beans (sadly), my favorite, can be murder if you don’t cook them thoroughly enough. Lentils, on the other hand, seem to be pretty gentle. They also soak up whatever flavor they are cooked in so they are a great “starter bean” if you want to eat a more vegetarian diet.