I've been vegan for a year, and was vegetarian for about 5 years before that. I went vegan for health, ethics and the environment, but each of these reasons has a different relation to the question at hand. While personally I would not eat lab-grown meat, I think it's an amazing opportunity to disrupt the meat industry and animal products market.
Ethically, there would be nothing wrong with it. On the contrary, it would drastically decrease the number of animals killed in the meat industry. For more information on how they grow meat in a lab without hurting animals, check out SuperMeat's successful Indiegogo campaign from last year. Environmentally as well - the decreased demand for animals used for food will also mean a decrease in supply. The fewer animals in factory farms worldwide, the less damage the meat industry will do to the environment, thus positively impacting climate change. For a more detailed introduction to the way animal agriculture affects the environment, take a look at Cowspiracy.
So, in theory, I have absolutely nothing against lab-grown meat. I think it'll be awesome and will help people not eat 'real meat', and thus help the environment and the animals. I still probably wouldn't try it though, let alone have it frequently.
The reason why I wouldn't eat lab-grown meat is that, well, it's still meat. Apart from my acquired dislike of meat texture, it would go against one of the reasons I initially went vegan for, i.e. health. There have been a variety of studies linking the consumption of animal products with most major causes of death - for example this study from the Harvard School of Public Health discusses how increased consumption of meat and dairy is linked to cardiovascular mortality, while eating plant protein is associated with cardiovascular health and, to put it crudely, reversing heart disease. If you want to know a little more about the ways animal product consumption is linked to mortality, while plant consumption to being healthier, check out Dr. Michael Greggor's talk and book.
Check out Joana's new project at www.kindredvegan.co.