Why is such a thing a problem for RCs, since the NAB "helps" and commentary has taught for decades such things as that such stories as Balaam and the donkey, Noah's flood, Jonah and the fish, etc., are fables, and that Divinely sanctioned events in Joshua's conquests were folk tales, and that certain historical events in the gospels did not literally occur as described. Etc.
This is the type of thing that the fundamental/evangelical movement rose up against in the last century, due to a common consent to basic core truths, yet RCs want us to join an overall liberal church, which has so redefined itself that fundamental type RCs now exists as sect of it, or in schism from it.
No thinking Catholic believes that the USCCB and their "helps" and "commentaries" are infallible. After all, this is the same organization which published a favorable review of "Brokeback Mountain". And let's not forget the sex abuse cover-up, which had all the appearance of a coordinated effort. Unfortunately, the Church and Her teachings are not necessarily reflected in the actions, statements and publications of the USCCB.
"As to the view of Christian tradition, it suffices to appeal here to the words of Father Zorell who maintains that the Bible story concerning the Flood has never been explained or understood in any but a truly historical sense by any Catholic writer (cf. Hagen, Lexicon Biblicum). It would be useless labour and would exceed the scope of the present article to enumerate the long list of Fathers and Scholastic theologians who have touched upon the question. The few stray discordant voices belonging to the last fifteen or twenty years are simply drowned in this unanimous chorus of Christian tradition."
http://www.newadvent.org/cathen/04702a.htm
Reading the Douay Rheims Bible eliminates the problem of strange interpretations, helps and commentaries.
yet RCs want us to join an overall liberal church, which has so redefined itself
Truth cannot be redefined. Sacred Tradition, Sacred Scripture and the Magisterium of the Church are interconnected and as such, one cannot stand without the other. If someone (even a bishop) promotes a different version of this fundamental reality, they are lying.