The taste and nutritive quality of meat has many, many factors going into it, and the genes are only one tiny part. For example, the amount of omega-3s in pasture-raised chicken, and their ratio to omega-6s is far better in pasture-raised chickens than in chickens subjected to confined animal feeding operations (https://apppa.org/The-Nutrition-of-Pasture-Raised-Chicken-an...).
My chickens are of the same genetics as gross grocery store chickens, but grow more slowly, get more exercise, require zero antibiotics, have vastly different flavour and nutritive quality, than those exact same genetics raised in factory farms.
The experience an animal has walking the earth--what kind of activities they engage in, what they eat, what they breath, what pharmaceuticals they're injected with--all have impact on the value of the meat.
What does "lab grown" even mean in this context? Sure, it's genetically identical, but what "lab environment" produces something like grain-finished meat? Which produces 100% grassfed beef?
It seems insanely simplistic to say that "we can grow this phenotype in the lab, so it'll be exactly the same as one raised in a barn or on a pasture."