Uh. There is absolutely nothing in the Mormon Word of Wisdom that says anything about chocolate. There isn’t even anything about caffeine. The phrase used is “hot drinks”, which has been interpreted by the Mor(m)on prophets to mean specifically coffee and tea (but not herbal tea). A particularly zealous bishop or stake president might counsel against caffeine consumption, but AFAIK they aren’t going to prevent you from going to a Mormon temple if you chug a case of Red Bull and Bawls every single day.
Source: raised Mormon, was active for 25-ish years, former missionary.