There's nothing to add to this:
“This morning, for the last time, priests will offer the Holy Sacrifice individually and simultaneously on the numerous altars of St. Peter's Basilica. Bringing to an end a centuries-old practice, which has survived plagues, wars, the capture of Rome and Vatican II.” https://t.co/D3sKlJSVw9
— The Catholic Traveler (@MountainButorac) March 21, 2021
Nothing, except this: this order was by FRANCIS (Jorge Mario Bergoglio). He ordered it. He may have used an irrelevant machine cog in the wrong dicastery to initial the document, but it all came from him. Seeing those throngs of young priests celebrating Mass after Mass in the many altars of the Vatican Basilica, a tradition that dated from the very first ages of side altars in the Old Basilica built by Constantine, was obviously something that rattled him.
Fine: there are hundreds of churches and thousands of Altars in Rome, and there's nothing he can do about it.