63. The high point of all liturgical action is the celebration of the Mass, in which the Eucharistic Prayer or Anaphora in turn occupies a pre-eminent place.[GIRM 78] For this reason, the approved translations of the approved Eucharistic Prayers require the utmost care, especially as regards the sacramental formulae, for which a particular procedure is prescribed below, in nn. 85-86.
64. Without real necessity, successive revisions of translations should not notably change the previously approved vernacular texts of the Eucharistic Prayers which the faithful will have committed gradually to memory. Whenever a completely new translation is necessary, the principles given below, in n. 74, are to be observed.
Michael Joncas has identified the Eucharistic Prayer as the sung theology of the Roman Rite. LA 64 strikes me as problematic and needlessly legislative. As language changes, so should the translations. New generations will memorize new texts.