Hypothetical question. Let's say this fruitions and is widely popular. Wouldn't that mean we would simply stop rearing cattle and poultry? Would that mean the species will go extinct? Now isn't that cruelty.
I imagine that, no matter how popular this gets, there will always be a market for real cows, pigs and chickens. It's just going to end up being a high end luxury market. A whole animal for roasting is something that will never be able to made in a lab. Also from what I understand this process produces fairly homogeneous meat, meaning you're probably going to need a real animal to make more interesting cuts, or 'bi-products' like heart, marrow and liver. Combine that with the fact that there will probably also always be a market for real leather (which will also become a high end luxury product) and I can see cows being reared for a long time after this process becomes wildly popular .