In the picture, if a player stands on the green block and the pistons recieve a 4 redstone tick pulse; the player will not be pushed upwards with the block and will fall through. I had some elevators that used this mechanism and functioned well, prior to 1.13. If the pulse is longer by 1 redstone tick, it seems the player position updates accoringly.
Unable to reproduce on 1.15 prerel 1