Evidently, the U.S. Department of Transportation (the FAA's parent) is going to evaluate the standards used by the FAA in certifying how quickly a plane can be evacuated. According to the article, there is a concern that as seat pitches have become tighter, and more pax are choosing to take their cabin luggage with them, that past tests of plane evacuation speeds may no longer be accurate.
https://www.cnbc.com/2018/06/19/faa-...standards.html