Liberty/UA, which bought BN from Lion and Wolff, could be accused of a form of mismanagement by promoting the light jazz of Ronnie Foster, Bobbie Humphrey, etc. But they did hire Cuscuna to go through the vaults and release unheard treasures. The big advance occurred when EMI bought Liberty/UA and placed Bruce Lundvall, a longtime industry veteran and dedicated jazz fan, as head of a revived BN. The advent of CDs accelerated the process, and allowed the rerelease of long out-of-print titles.
Let's also credit the Japanese, who kept interest in true jazz alive during the dark days of the mid to late '70's.