The current plan is to have Redeem Gwent with options to buy all 4 decks. This is still not 100% confirmed but very likely.
I really like that option though I sorta wish I could get a spare copy of the BaW cards, I decided to order all 4 just so I'd have a spare deck for HoS (already bought one back during the Redeem Gwent for it)
I guess I'll just buy a copy of BaW at retail and gift the code to a friend