It would be interesting to see a more detailed study with a broader spectrum, on how eggs are affected, flavor, color, texture, nutritional properties... beyond just the cholesterol, fats, and fat soluble vitamins. Confined on commercial feed vs. pastured or free ranged on restricted feed which actually encourages foraging behaviors...
Let’s face it chickens are kinda lazy in that if they have all the food they can eat laid out buffet style in a trough right in front of them, why would they put all that effort into foraging? “Oh, look! A tasty bug... I’ll eat it! Maybe I’ll even nibble a bit of grass now and then too” Might happen in the circumstances laid out in this study, but there’s no actual requirement for the pastures chickens to provide for themselves.