In short, the article states that indigenous/ hunter-gatherer diets that were low in carbs produced perfect dental health and health throughout the body. The author states inspiration from Gary taubes.
Many conventionally minded articles and journal reviews ive read do state that all fermentable carbs can cause cavities, but they generally are explaining this action via plaque and bacteria theorem, not as systemically altering the body from the inside out and causing defects. Also, interesting the above referenced article states that many studies have failed to show that it is a specific set of missing nutrients that causes dental decay.
Edited: also, to just throw a wrench here is an article citing studies which found no causation for sugar in the diet and caries