Actually, the Church claims doctrine infallible, not your perceived "traditionalists". And he doesn't need to affirm the infallibility of the doctrine that he is addressing, he needs to confirm that AL is in line with this doctrine. Hence the possibility of a formal correction. The Church should never be a source of confusion for the lay faithful who are attempting to become saints while living their daily lives. The difference in pastoral implementation is unfortunate, as is condoning the reception of the Eucharist to those commit adultery. This is a direct result of the wording of AL and the "disagreement" about what Pope Francis is trying to say.