At the beginning of the week, the insider Catholic universe imploded when news broke that retired Pope Benedict XVI and Guinean Cardinal Robert Sarah had co-authored a new book defending priestly celibacy just as Pope Francis is considering an exception to the rule proposed during the Amazon synod.

In the fierce and polemical debate that ensued, the role of a pope emeritus was questioned while Catholicism’s conservative and progressive camps exchanged arguments over Benedict XVI’s intentions with the book, titled From the Depths of Our Hearts: Priesthood, Celibacy and the Crisis of the Catholic Church, which hit shelves Jan. 15 in France.

Though unprecedented is perhaps the wrong word to describe the bizarre episode, it was certainly odd, as Sarah, an active sitting cardinal who heads the Vatican’s liturgy office, took to social media to defend his credibility, issuing several statements and publishing correspondence between himself and Benedict – things that heads of Vatican departments don’t typically do.

However, this week’s episode could well have been Sarah’s “last hurrah,” as the Guinean cardinal is set to turn 75 in June, meaning he will be required to submit his resignation after having reached the formal age of retirement for bishops and cardinals.

Sarah is just one of many possible shakeups that could take place around the Vatican this year as Francis’s reform of the Roman Curia unfolds, with several major department heads already 75 or older, who have yet to step down.

Heavy-hitters such as Spanish Cardinal Luis Ladaria, head of the Vatican’s doctrine office, and Canadian Cardinal Marc Ouellet of the Vatican’s office for bishops will both turn 76, yet both are widely seen as having Pope Francis’s backing, so he might keep their resignation letters sitting on his desk, and not accept them just yet….

The above comes from a Jan. 18 story in Crux.