Have you read Judge Leon's Opinion in the Smoking Everywhere & Sottera (dba njoy) versus FDA case?
Judge Leon essentially described two classes of electronic cigarettes. Any company that made a health claim (e.g., you can use these to stop smoking) would be regulated as a medical product under the Food, Drug, and Cosmetics Act. Big Pharma's product would not allowed to be sold until after the company went through the entire New Drug Approval process that all drugs have gone through.
The other class is recreational. If the manufacturers and/or sellers make no health claims, the FDA could regulate their product(s) under the tobacco Act.
So if Big Pharma produces a prescription type of e-cigarette that drug approval does NOT force all other e-cigarettes off the market auto-magically.
Funny how a company can say QUIT SMOKING using LAser or Herbal stuff but an Ecig cannot ??? they are NOT FDA approved or a drug !