The Church’s “extraordinary” magisterium, capable of binding the faithful in faith and doctrine, can proceed solely-papally or papally-episcopally ; but her “ordinary” magisterium, also capable of binding the faithful in faith and doctrine, can proceed only papally-episcopally . As Francis’ move on the Catechism hardly qualifies as papal-episcopal, and there being no such thing as an ‘purely papal, ordinary, magisterium’ (the term itself seems an oxymoron, implying that some significant points of Church teaching have been taught only by popes!), then Francis’ views on the death penalty might (I stress, might, given the infallibility concerns above) contribute to the Church’s ordinary magisterium but they do not, and cannot, control it.
How to sum up the traditional understanding of this matter so far? Maybe thus: If it’s not extraordinary, it’s at most ordinary, but if it’s ordinary, it requires popes and bishops around the world and over a long, long time , and not just a pope in a claim or two.
All of which is why the questions surrounding the death penalty impact not only that very important social and civil issue but also the Church’s understanding and operation of her own magisterium.