If that's the case than the MTA and/or its insurers have gotten a lot more cautious in the last 30 years, since they apparently rejected the idea of putting skirt extenders on some of the R-26/28/29 Redbirds for use on the B Division to make up for the car shortage between the time the 63rd St. connector officially opens for V train service and the R-143s arrive.
The idea makes sense to me, but reporttedly, the fear of kids riding on the door platform ledges outside the cars shot down the idea among the MTA brass. God knows what the same people today would have thought about running trains with a one-foot gap between the platform and cars, especially on the elevated lines (little signs on the el supports at street level saying "Beware of falling people," I guess).