The best part about the “I’m with you to the end of the line” bit is that they made it gayer. It could have been Steve and all the Howlies charging into battle, and instead we got just Steve and just Bucky, sharing a small, touching moment at home.
There are arguments for queerness either way, sure. Bucky saying anything at all to Steve ever in those movies can be construed as pretty gay in general. But the fact that they made the moment more personal and more intimate in order to make the end of the film more emotional. It’s just. Guys, it’s so gay.