It’s perfectly reasonable to imagine a kid whose first choice is Penn, but would be happy to attend an EA school if she doesn’t get into Penn. Assuming applying EA provides a bit of a boost (I don’t know if that’s true), it would make complete sense for that kid to apply ED to Penn and EA to, say, Univ of Chicago. In that case, Penn’s new policy makes kids in that situation worse off while providing no benefit to Penn.
If my son’s first choice school has ED, but others on his list are EA, I will definitely encourage him to apply to the first choice ED and then EA to others, obviously assuming the schools’ rules allow this. Even if there’s no EA boost, there’s a lot to be aid for the sheer relief and peace of mind that comes from knowing on December 15 that you’re in to a school you’d be happy to attend.