A lot of people aren't real clear on the distinction between CB and TR. I don't know why they wouldn't make that distinction on the sheet, but maybe it's a wholesaler or something who doesn't know the difference?
There is a facility called Sustainable Aquatics that captive-breeds several different fish (clowns, Banggai cardinals, fangblennies). These are fish from parents that may have been either WC or CB themselves, but the young are "conceived", hatched, and raised in captivity from the git-go. They've never been in the ocean.
Sustainable Aquatics also has a division called Sustainable Island, which pays native residents (I think in the Solomon Islands, but I'm not sure) to capture larval fish, which are then raised back in the States at SA's aquaculture facility. The three tangs you mentioned are some of the species they raise (but NOT breed) in captivity. They probably came from SA/SI.