It appears that the identity of the new Carbonized Black Series 2pk has been revealed via an early leak/link on Amazon. The set includes Ahsoka Tano and HK-87 but the description on Amazon makes no mention of carbonization. The info I found for this set last week clearly calls them out as “Carbonized”. No word when they’ll be officially announced but they are available for preorder now (delivered from the UK).

Thanks to smolbekel for the additional info.