User blog comment:The Dragon Demands/Season 5 trailer officially released/@comment-1600847-20150130164618/@comment-5014364-20150130182914

...re:Trystane....I wouldn't put anything past the writers, though I sure hope not.

...I strongly believe that they were holding off on Lady Stoneheart for the Season 5 finale, because otherwise they were afraid they had nothing as strong as the Red Wedding to serve as a season climax.