Well, my personal one would "Did they finally manage to get Joan of Arc right"? As someone who wrote an extensive paper on "Truths about Joan as a Military Leader" for my medieval history exam at the university, I'm still amazed of how Pdx always managed to drop the ball BIG TIME on that one since EU2.
Ah, and an anti-complaint: Castille declares war on Tibet in 1501, and the stray EU4 fanatic appears to "explain" how "(whine) If I want realism I would read an history book! (/whine)!" The early days of HoI3... what a nostalgia!