To add to what everyone said above, I too would love for them to deepen Noct's combat. Personally, and I'm sure my opinion is in the minority, I enjoyed the Episode Duscae "deck of cards" system where you set a weapon to each type of attack. I think it would be neat if EP Noctis gave us a new accessory similar to Armiger Unleashed - and equipping the new accessory would let us switch to that battle system by choosing which weapons do what.
And if not, then at the very least give us a second (or even third) accessory to equip to Noctis that deepens his Armiger Unleashed. That way the Royal Edition AU is level1, and EP Noctis would bring it up to level2/level3 by giving the player even more skills, combos, and moves (I loved how AU gave us the "pole dancing" move from earlier trailers, would not mind if they deepen AU further and reference old gameplay mechanics from prior trailers even more! maybe more Noctis parry animations?)