I see why GRRM wanted included in HOTD this new revelation about Targaryens knowing about the White walkers , but knowing how anticlimatic the resolution of the "Great Winter" was in GoT , this part of the show didnt sit well with me and felt cringy. It wouldve been better left as a minor foreshadowing in some throwaway dialogue. But as seen in the weeks ahead trailer, the song of ice and fire secret will be promineng trough the series, sigh...