I don't know, you hear it quite often but I've never seen any evidence that OB peacocks come from Mbuna.
Does anyone know of a thread where someone bred a Mbuna with a peacock or Hap? because a lot of other haps like Ahli and even compressiceps have an OB variation.
Either they are being selectively bred with Mbuna, or the blotches are just a naturally occurring mutation in both types of fish.
I`d just like to see some clear evidence if that is really their background.