There’s never been a single reported case of popcorn lung caused by vaping, and the vape manufactures have basically all chosen to switch to something other than diacetyl out of an abundance of caution. It was only ever in some of the “creamy” and popcorn type flavors anyway.

That said, don’t start vaping. It’s great as harm reduction because it’s better than cigarettes, but unless you’re using it to stop smoking cigarettes, don’t vape.