Yes, it is for sure. I haven't seen it explicitly related to veganism in the past but I have seen people say that because we can know better about the ethics of being omnivores, we can do better and make it work by special designed diets - which is a kind of tech.
The idea with transhumanism is that somehow, we can know what would make us better (what does that mean?) humans, and then make that happen through technology. There is an implied criticism of our natural bodies in that, be it the way they see, or exist in space, or are sexed, or what they need to eat.