No. You can be a healthy vegetarian if you're willing to put forth the effort and research, but it's impossible in the Primal sense. Grok would have died because he would have lacked the scientific knowledge to make "complete proteins" out of vegetarian sources. Vegetarianism is an elitist luxury that only exists in the modern world. Even so-called "ancient cultures" that were vegetarian have only existed for mere seconds in the grand scheme of things.
Besides, I doubt Grok ate very many vegetables, anyway. I feel the current iteration of the Primal Blueprint, while improved since the last version, still puts way too high of an emphasis on vegetable intake - probably for a reason, since it's much easier to get the masses to embrace vegetables than liver, kidney, heart, tongue and brain. I feel a diet high in organ meats, moderate in muscle meats, moderate in starchy tubers/roots/squashes and moderate to low in fruit with low quantities of fibrous vegetables and nuts is the ideal human diet, but that's just my opinion.
Don't put your trust in anyone on this forum, including me. You are the key to your own success.