People were very helpful below in helping me find information about the new Missal in Spanish for the US. As indicated in the discussions in this list that alerted me to the changes, our bishops decided to correct a Babel of Missals used by priests from different Spanish-speaking countries and align ours with Mexico’s. Very many people on this list know more Spanish than I do, but for those who don’t who are confronted with bi-lingual parishes, all I can say is I have a great school dictionary and it clearly labels words as “Esp,” “LatAm,” and “Mex.”. My advanced Spanish composition book is full of notes: “use this word in this country but NEVER in that country.” So our Bishops had a fairly substantial problem and they have decided.

This goes into the details quite well.

https://www.ocp.org/en-us/blog/entry/introducing-the-changes-in-the-misal-romano-third-typical-edition