The Spanish missal and lectionary are not being revised for translation errors, as is the case with the English. The better word would be reviewed. The Spanish books that we use in the USA are perfectly fine as far as the translation goes. They have none of the errors of the English. But what they want to do is to rework them in a North American Spanish edition.
The idea of a North American Spanish is not a new one. It did not begin in Church circles. Today, when more than 30% US citizens are first language Spanish speakers and have a Spanish that is very properly a Spanish of the United States, it is becoming more common in educated circles to use that register of Spanish instead of the Mexican, Caribbean, Latin American or Spanish.
When the committee met to discuss the Spanish in the mass, it was found that many of the words, though they are correctly translated, are not universal to all Spanish-Speaking North Americans. A simpel example: vosotros vs. ustedes or tu and su. Both are correct. The question is which is the appropriate form for American Spanish. Like this, there are many little details in the missal that are going to change.
Then of course there are the movements of certain elements. But those have nothing to do with language. That has to do with uniformity.
Fraternally,
Br. JR, OSF