Originally Posted by Spider-Fan
Dude, Cap 3's BO would go down TREMENDOUSLY if you killed off Steve Rogers and made Bucky Cap. Interest in the character is immediately lost, and the film will suffer. Thor could make sense given Hela's involvement and such, but that still involved Hemms and he isn't actually dead (he would be "technically" dead). But, I think a Thor film based on Ragnarok would be a better Thor 3 than escape from Niffleheim. (most probably would agree). You can't permanently kill Thor or Cap, and then expect the BO to increase. It will only lose money and there is little logic in doing it financially.
While the Han-Solo-in-carbonite-esque apparent death is a cool cliffhanger, I don't see Marvel doing this to end a film. Remember, they didn't even end CA:TFA with this type of cliffhanger, where it would have made the most sense (they couldn't even wait until after the credits!).
I shouldn't rule it out outright, I haven't sat in on any meetings with Feige and I don't know what he's thinking, but based on what we've seen so far
, I don't see it happening.