What about masses for the saints like Padre Pio?

Yes, this is but a rumor, but it is a well-founded one. What lends serious credibility to it is the fact that this report does not simply appear on “Joe’s Blog” on the blog of Una Voce in Malta, citing “reliable sources close to the Holy See.”
Una Voce is a Vatican-recognized international organization that promotes the use of the Indult Mass, now also called the “Mass in the Extraordinary Form”, i.e. the 1962 (John XXIII) version of the Traditional Latin Mass. Formerly, the president of Foederatio Internationalis Una Voce was the famous Michael Davies (1936-2004), whose poor scholarship and half-baked theology was masked by the prolificacy of his writings, his pleasant style, and the overall traditionalist appeal of the positions he defended.
Meanwhile, Mr. John Zuhlsdorf — “Father Z” — has chimed in to quell people’s concerns: “Piffle. Even, bull piffle! No. Won’t happen. In addition, I checked with my various peeps. No. Won’t happen. Can’t happen”, he asserts dogmatically, before informing his readers that he has turned the comment moderation queue ON. Precisely why anyone should think that Mr. Z’s mere say-s0 and “checking with various peeps [people]” should trump Una Voce‘s “reliable sources close to the Holy See” is anyone’s guess — especially in light of what has transpired in the Vatican in the last four-and-a-half years, which a mere five years ago the likes of Zuhlsdorf & Co. would have assured us all could “never” happen!

How do the changes to the '62 missal compare to the '37 missal?