I flew into Rome on this day last year. Everything seemed normal except I took the Leonardo Express train purposely the extra stop to Tiburtina station (not Termini the main station) so I could buy a bus ticket for my next day ride to Siena (where I was studying and living) and the bus station was closed because of the holiday. This really turned out to be a minor inconvenience. I also remember seeing on the news that a the pope did a mass that day in the Vatican and it drew a huge crowd. So maybe Vatican/Catholic tourist activities would be crazy that weekend but otherwise Rome seemed manageable.