So what exactly are they smoking?
They are not kicking the addiction, but they are not smoking.
Guess it all depends on how literal you want to be with your verbs. On a strong technical level they’re vaporizing rather than smoking, but I don’t see a point in quibbling. In the community “quitting smoking” means quitting nicotine, nobody congratulates anybody for quitting smoking if they’re method is switching to chew, still on the nic is still on the nic.