The latest is that Pope Benedict XVI would not approve since at one time he wrote that "dissent from the ordinary Magisterium should be disclosed privately to Church authorities." Yet, what Father Weinandy has done is not to dissent against the "ordinary Magisterium," but to a Pope who has created confusion, promoted insult and promulgated what is clearly heresy in Amoris Laetitia and in countless other statements from his homily of the day.
Canon 212 clearly gives the faithful, as their competence provides, the right and duty to raise concerns to Church authority. Friar Weinandy is more qualified than most. There is no conflict between Canon Law and then Cardinal Ratzinger's statement.
Recommended reading on this can be found at Dominus Mihi Adjutor, the blog of Fr. Hugh Somerville-Knapman, OSB and Australian Benedictine monk and priest in England.