From a reader…
As a recent convert and a lawyer (but definitely not a canon lawyer), in view of Pope Francis’ recent endorsement of the broad view of AL, can the Congregation for the Doctrine of the Faith issue a binding interpretation of AL.
Sure. The Congregation can do this. We have the famous case of the explanation of Ordinatio sacerdotalis.
However, just as in the case of Ordinatio sacerdotalis, the Holy Father would have to sign off on such a document and order its publication.
Even were the CDF to draft such a thing (itself hard to do without the knowledge of the Pope), is it likely that Francis would approve it?
When it comes to documents, Francis holds all the cards. Congregations are merely extensions of his own office. He delegates his authority to group A his task about subject A, to B his task about B, etc.