Why "Anglicanorum coetibus" does not control one's reading of Canon 277
Three documents inform one’s understanding here: the apostolic constitution Anglicanorum coetibus (4 Nov. 2009), the Complimentary Norms issued by Congregation for the Doctrine of the Faith the same day, and an “official commentary” on the constitution by the esteemed canonist Gianfranco Ghirlanda of the Gregorian University. Two points emerge from these sources.
First, none of these documents even mentions the clerical obligation of continence as set out in Canon 277, so any claim that they obrogate from the express language of Canon 277 can be offered only ex silentio. I believe, however, that the weaknesses of ex silentio arguments against clerical continence are apparent to anyone who reads my analysis of Canon 277; those observations apply here as well.
Second, and even more decisively, while an 'apostolic constitution' is the highest form of legislative document used by the Church (see Morrisey, Papal and Curial Pronouncements  at 14-17) such a document must be interpreted in accord with the general principles of canon law (cc. 16-21) including: applying it to matters it intends to cover, and declining to apply it to matters it does not intend to cover. Anglicanorum and its Complementary Norms, by their repeated and express terms (passim), apply only to former adherents to the Anglican communion, and to no one else. Nothing in Ghirlanda’s commentary remotely suggests otherwise. Therefore, regardless of how Anglicanorum might (or might not) impact former Anglicans in this area, it cannot control arguments concerning the operation of Canon 277 for any other clerics in the Church.
I have some other comments on Anglicanorum, but these two suffice, I think, to address the question presented to me.