Yeah but they found things in the normal beebread that all the others eat that basically inhibit the genes that allow the larvae to become a queen. Ergo, the lack of beebread is important as well. Mostly skimmed the article because it's late, but I didn't see much actually specifying whether or not the royal jelly leads to Queen Bee genes being expressed, only that beebread stopped them from being expressed. If I read that correctly, the article does imply that feeding a larvae royal jelly and it becoming a queen are merely correlated, as feeding a larvae royla jelly implies that you wouldn't bother with beebread (assuming the royal jelly to be a sufficient source of nutrients, which stands to reason).