Yes, this is an accurate statement. The black berkey's were designed and introduced by the US Berkey company. Prior to the BB's, the white ceramics were the cats meow. The black berkey's go above and beyond the ceramics in their filtering abilities. This is why NMC(New Millenium Concepts) had to create the PF-2's. The black berkey's addressed much of what the Pf-4 add-ons did, so NMC designed the PF-2 to match and pick up where the black berkeys left off. So, the BB and PF-2 combo is the newer filter technology....as opposed to the older ceramic & pf-4 combo.

This article explains the matching up of the filters well:

how many berkey filters are needed