You've no doubt seen, but other NPCs in the DLC have the same thing. Leda has unique dialogue if you ignore her in Mohgwyn speak to her for the first time at Highroad Cross I wonder if Hornsent has special dialogue for a Highroad Cross first-time meeting, or if Hornsent/Leda have special dialogue if you speak to them for the first time post-charm-breaking, or if Freyja/Ansbach have special dialogue in the Specimen Storehouse, or if Leda's gank-fight speech is different if she's never talked to you