Okay, let’s talk about this, since I haven’t seen anyone else talk about it.
In the original story arc of The Winter Soldier, when Bucky is back to being himself, Steve gets shot. Bucky then takes up the title of Captain America to carry on for his friend. Both Cap movies have seen Bucky pick up the shield in an obvious
attempt at punch in the face of foreshadowing.
Now, Chris Evans signed on to do six Marvel movies, only three of which he has completed (they are not counting his Thor 2 cameo). Sebastian Stan, however, signed to do nine Marvel movies, having only done two now.
If it isn’t obvious, I don’t know what is.