For what its worth, I sent an email to WD author Ori Hofmekler regarding WD and veganism, and here is his response:

"As a vegan you must be careful with your protein intake to avoid amino acid deficiencies. Most plant foods are deficient in certain amino acids, most notable the amino acids Lysine and Methionine, and obviously their respected derivatives – the amino acid Carnitine, Cysteine and Taurine, all of which play critical roles in regulating energy production and immune functions. Some vegan foods such as brewer's yeast and bee pollen do contain all the essential amino acids, but nonetheless are reactive and allergenic to some individuals. My recommendation is to consider a healthy lacto vegetarian diet. It has been used successfully by some of the healthier societies in the Middle East, Mediterranean, Europe, Africa and Asia."