In the Last Supper account in the Eucharistic Prayer the Latin has “qui pro vobis et pro multis effundetur in remissionem peccatorum”. “Pro multis” literally means “for many” (or “for the many” – remember Latin does not have a definite article, so cannot make the distinction we can make in English). The Latin does not say “pro omnibus” or “pro universis” which, obviously, would mean “for all”.
The translation into English authorised by Pope Paul VI had “for all”. It validly consecrated in English-language Eucharists all around the globe for decades. It was argued that those who said it should be translated “for many” were schismatics falling into Calvinist heresy.
But times have changed. Now “for many” is in. “For all” is definitely out. The same goes for German. “Für viele” is soon to replace “für alle”. The Pope himself has made this crystal clear (translation here).
Just to be clear: when Jesus used Aramaic, he meant what we mean in English when we say “for all” and in German when we say “für alle”. Roman Catholic teaching, and I believe Christian teaching, is that Jesus lived, died, and rose for all. It is the Latin original that is incorrect.
The catechesis that the Pope requires is that people be taught that “for many”/“für viele” in the Eucharistic Prayer actually means “for all”/“für alle” – but we are not allowed to translate it to be what it actually means.