The FDA has a "pre-market" tobacco authorization application, which companies offering new vapes are required to submit. The FDA is supposed to allow these only if the new product benefits the public health (e.g. by adult cigarette smokers switching to it, and it being less harmful than cigarettes).
The FDA has, in general, been allowing some PMTAs for tobacco-flavored or unflavored vapes, and been denying PMTAs for flavored vapes (by convention, tobacco-flavor is not typically considered "flavored").
The respondents are companies whose PMTAs for flavored vapes were denied. The 5th Circuit held that the FDA's denial of their applications was improper. This case will be argued on December 2, 2024, with a decision expected by June 30, 2025.
This question will resolve YES if the FDA wins (the Court reverses the 5th circuit), NO if the FDA loses (the Court affirms the 5th circuit).
For more, see the SCOTUSBlog case page:
Edit: disclosure/brag - I co-authored an amicus brief in this case, but I have no inside information about the outcome.