Is the Mass changing? No! Yet the official text of the Mass of the Second Vatican Council - The Roman Missal of Pope Paul VI - has always been published in the Latin language. When we celebrate Mass in English, we are using an English translation of that Latin Missal. So it is the English translation of the Mass which is being revised, not the Mass itself.
The link in the menu above will give you access to the revised translations of the parts of the people and the parts of the priest.