This seems to a further stretch of the seamless garment.
“There may be a legitimate diversity of opinion even among Catholics about waging war and applying the death penalty, but not however with regard to abortion and euthanasia." - Cardinal Ratzinger
Don't take the bait by focusing on the issue itself (i.e., the death penalty). The point is that no Pope has the right to wake up and say, “You know what? I'm going to take a perennially held teaching of the Church and change it by fiat. I'm going to issue a statement and that’ll be that.”
We are in dangerous waters here.