Really. Remember? If Roma no locuta, the causa ain't finita.
Your quote from the catechism about interpreting "authentically" refers to this authenticity being such that other Catholics are bound to believe the same.
For instance, a popular topic lately, I can believe Jesus' "brothers" are cousins and another Catholic can believe they are step-brothers. The Church has not "authenticated" either view. I am free to believe either one and I have no claim to force another Catholic to believe my interpretation.
SD