@Big:
I think we could expect quite the opposite. Remember how Oda depicted Crcodile during Marineford? Attacking Whitebeard, Sakazuki, the executioners? Oda really tried to hammer Crocodile's strength into the audience's mind, even as Crocodile had been the defeated villain over 300 chapters ago.
I think there's also a quote from Oda where he basically says that he doesn't like it that characters who were defeated in the past to be written off as "weaklings" by the audience.
Dunno, Moria was discarded pretty quickly.
But I hope you're right. Marco is one of my fav characters and I hope we get to see him kicking ass with his full powers. His fight with Kizaru got cut too short.