10 Reasons Why Legacy Characters Are The Future Of The MCU
2. The Original Characters Would Reach Mythic Status
Imagine a new fan watching a movie from the Marvel Cinematic U for the first time, and its the second or third iteration of Bucky or Falcon as Cap. Thanks to allusions within the movie, they'd understand that there used to be a man who wore the costume and bore the title. They'd understand that he was a legend, and that whomever currently held the mantle had a lot to live up to.
It's the equivalent of watching Star Wars for the first time and hearing Obi-Wan talk about the Clone Wars and Luke's father. The mind begins swimming with ideas and images about what that looked like and the battles they fought together. That one small dialogue exchange in Star Wars did wonders for creating a lived-in history for that galaxy.
The benefit of having a similar thread in future Marvel offerings is that new fans can actually go back and watch all of the films that came beforehand, being able to see these myths and legends play out for themselves (the quality of each notwithstanding, of course...).