I know they had Sam be Captain America in the comics, but seeing those promo images just makes me think the shield is superfluous for Falcon, and would actually get in the way of his wings. He can already use his wings to shield himself, and he can use them offensively as well, so the Cap shield makes no sense, other than "Cap has to have a sheild because it's iconic." I'd rather they just didn't have the shield, or better yet, didn't try to make someone else "Captain America."
I know this is reharshing an old argument, but while Cap may be a 'symbol,' it was Steve Rogers who was Captain America. They should've just had Falcon get renamed as "American Eagle" or something, and ignored using the shield and iconography, and trying to make him live up to something/someone that is impossible to do.
Bucky always made more sense of taking up the mantle (similar powers and had more of a connection to Cap than Sam did), as he also did in the comics, but I think the other part that doesn't make sense in the MCU is that everyone knew Steve Rogers was Cap, and knew that he was "lost" fighting Thanos (even if the public didn't know he didn't die but chose to live a different life). In the comics, secret identities were more important, so you could replace one masked hero with another and the public wouldn't know. So why try to make someone take over a role that was connected to one man? I know they tried to explain it to some degree in The Falcon & the Winter Soldier, but the government already failed with one attempt to replace Steve, so it doesn't make sense, except from a P.R. point of view, that they'd need to try it again.
I'm hoping that this movie just has Sam give up the mantle of Captain America and just be his own man, but I doubt that'll happen. The real reason to replace Cap is for the name value with moviegoers, to try to sell more tickets.