I think the card distribution can now be updated, because it has been revealed that each class will have access to 14 cards this expansion. (6 Regularly and 8 (from the two pairings). It has also been revealed, that every class will have three legendaries. One regular one and two from the pairings.
Source: https://www.hearthpwn.com/news/7508-scholomance-academy-community-ama-facts-card