On languages, I certainly give the nod to St Peter speaking Aramaic while out and abouts but Hebrew when in a ѕуηαgσgυє. Jews are picky about that. Aramaic, while the lesser of the two in the Jєωιѕн world, is said by the same Jєωιѕн world to be the older of the two. Aramaic is held in high esteem because it is said to be the language of Abraham. As for Aramaic and Hebrew, they use the same alphabet and have the same pronunciations.
The switch to Latin, while I don't have the details in front of me, can be safely trusted to the guidance of the Holy Ghost and the hierarchy of the Catholic Church. We can trust the Church on matters from the days of Our Lord to the election of Pope John XXIII. We can trust the Church now but that's an act of supernatural faith.
Pope Francis' words can be construed as a sloppy Hermeneutics of Continuity. He can think it's all a fad and he can be surprised at the youngsters who are attracted to Catholicism.
I myself will always be baffled by people who enjoy the novus ordo. When it's a clown mass, you can at least laugh.