[Jtsummers]

The linked document is from 1992 (commissioned in 1986). However, I don't know when the ideas in this section became part of Catholic teaching. The Catechism assembled ideas rather than created them, they already existed in other sources (biblical or prior writings of the Church or scholars). Thomas Aquinas and others are cited in the footnotes so at least the core of the idea (that the Bible isn't meant to be entirely literally interpreted) within the Church dates back to their writings. However their acceptance (that is, whether the Church declared these ideas official canon or just valid non-heretical ideas), I can't say when that happened.