Maybe not a “law” per se but likely built into the consumer product safety rules.
kind of but not really.
the hand-held remote is a “quasi-local” device since you have to be within range of the GD controller for the RF signal to reach it. Even if someone is dumb enough to close the door on someone because they didn’t check to see if anyone was there before they pushed the button at least the idea is that they should be checking if they are close enough to use the hand-held remote.
A zwave controller (or myQ or any other such device) isn’t limited by that and can be operated from literally anywhere in the world that has a connection to your home automation system/network. It’s to prevent someone who has no way obvious way to see if someone is under the door (not many people have cameras in the garage) from closing it without at least giving a minimal attempt to warn someone that the door is about to close and to get out of the way.