I found this:
The delay gives manufacturers four additional months to sell products that were on the market before Nov. 8, 2016. After Sept. 9, 2020, those products must be removed from the market, unless a PMTA has been accepted for review by the FDA, in which case they may remain available for up to one year while the FDA conducts its review.
All products introduced after Nov. 8, 2016 (and all
prefilled pods and cartridges containing flavors other than tobacco and menthol, no matter when they were first introduced) must receive FDA marketing approval (an approved PMTA) before they can be sold. Every single vaping product, including hardware and all e-liquid (even tobacco-flavored and unflavored), is subject to the PMTA requirement.