It seems like we are drifting away from main topic. Vegans can have any reasons they like to follow the idea or philosophy like you have said - climate change pollution or anything they like to pull. It's totally fine as long as they not pushing everyone else to follow. If they like to eat lab grown meat - I cant be happier.

More important question here is whether lab meat objectively (and objectively is a key word here) has any benefits over traditional meat.