After I defeat the dragon in Kynesgrove, I am given the objective to talk to Delphine, but the quest-specific player dialogue does not appear.

I went into the Creation Kit, I looked at Delphine, and it looks as if Delphine has lost her lines pertaining to MQ106. (e.g. "I owe you some answers, don't I?" and responses to default PC questions)

It would seem as simple as to fix the missing dialogue, and, I would have done just that, but, I still don't have a grasp on Papyrus scripting in terms of initiating dialogue between the Dragonborn and Delphine.

This issue could have affected other NPCs and their bundled scripts.