I know a lot of vegans who indulge in sugary fruits and dishes. Most of my vegan peers, in fact. At the same time it is quite possible to keep high-fat, low-sugar vegan diet (or even plain vegan keto). It boils down to any above-ground plant, no fruits, various nuts, and a lot of oil - olive, avocado, coconut oil. And soy products of course. It is much healthier than consuming tons of fruits, destroying your metabolism and teeth.