Different goals and different approaches. Veganism rejects animal USE for human purposes. It rejects the commodity status of animals, the instrumentalization of them.
Using animals to make lab-grown flesh for others to keep commodifying them and instrumentalizing them is NOT A VEGAN STANCE at all. In fact, it goes against the vegan goal of changing the mindset that animals are here to be exploited by humans as resources, as slaves, as if they were products, COMMODITIES.