Cardinals Raymond Burke, Joachim Meisner, and Carlo Caffarra submitted along with Brandmüller the short list of yes-or-no questions, called a dubia. It is a formal way to ask for clarity from the pope about doctrine.
When Pope Francis didn't respond to the cardinals, they made their concerns public. He has yet to respond, although many prelates and papal collaborators have criticized the four cardinals.
Burke said the cardinals are considering a "formal correction" if Pope Francis doesn't address the cardinals' concerns. He doubled down on this promise last month in an interview with EWTN. He told Raymond Arroyo "of course" the possibility of a formal correction still stands, as it is the "standard instrument in the Church for addressing such a situation."
Burke suggested in a subsequent interview with LifeSiteNews that such a correction would "probably take place sometime after" Christmas, New Year's, and Epiphany.
Burke "did not say," Brandmüller said, "that a potential fraternal correction – such as the one quoted in Galatians 2:11-14 must be made publicly."
"I believe that Cardinal Burke is convinced that a fraternal correction must in the first instance be made in camera caritatis," meaning in private, said Brandmüller.
He said that Burke's comments on a formal correction were not made on behalf of the four cardinals, although they may share his sentiments: "I must say that the [cardinal] has expressed his own opinion in complete independence and [it] may of course be shared by the other cardinals too."
Brandmüller said the cardinals "expect a response to the dubia as the lack of a response would be seen by many within the Church as a rejection of the clear and articulate adherence to the clearly defined doctrine."
Critics of Amoris Laetitia say it contradicts Catholic moral teaching by creating the possibility for a change in sacramental practice that would allow active, unrepentant adulterers to receive the Sacraments.
Prelates like Cardinal Walter Kasper say it does in fact allow for such a change, and that such a change is a good thing.
Other bishops and Catholic leaders say there is no way that Pope Francis can enact such a revolutionary change via a footnote, and that the only proper way to interpret Amoris Laetitia is through the lens of all Church teaching on marriage, family, sexuality, and the Sacraments.