First of all, while some of the gospels in the Nag Hammadi library (but nothing in the Dead Sea Scrolls) disagree with the canonical gospels on certain points, to say that they highlight “glaring historical discrepancies and fabrications” is a gross overstatement.  And certainly these scrolls do not “confirm” in any way Brown’s theory about the makeup and “agenda” of the modern Bible. Moreover, I have yet to see a single shred of evidence that suggests that the Catholic Church fought against the release of the Dead Sea Scrolls or the Nag Hammadi library.  And why would they?  The Dead Sea Scrolls pose absolutely no threat to “orthodox” Christianity, and the threat posed by the Nag Hammadi library is marginal at best.   There has been a considerable delay in the release of some parts of the Dead Sea Scrolls, but this has everything to do with scholarly wrangling and nothing to do (at least to my knowledge) with the Catholic Church.