https://www.fantasyflightgames.com/en/news/2015/6/16/taking-the-black/

Dat NW Plot! This just made me go squee for some reason.

Fans of the show be like, "TOO SOON!"

How the bloody hell did they make cards so **** sexy?

we felt that investing heavily in new plot cards would rapidly increase the strategic scope of the game.

Called it! - https://community.fantasyflightgames.com/topic/175300-cant-wait-to-buy-27-core-sets-so-amped/page-3#entry1660605

Anyway, I agree this is really smart. Until the card pool gets deep enough that you can really do much besides work with the core set shells, adding plots is going to be a huge benefit to diversifying what the card pool is capable of. I think this will be highly impactful.