Some doctors may have been wrong, but that doesn't mean nobody knew cigarettes were dangerous. I'll save my time and assume that if you're this unabashedly wrong about this, you're probably as unabashedly wrong about everything else too
I'm ignoring it because you don't really have anything to say besides "we don't know what the health effects of lab grown meat will be" when it's quite literally exactly the same as normal meat. It's like complaints about GMOs. The process of producing it may be different, but the physical material that you consume is literally identical on a chemical level. It's nothing like cigarettes.