Another foreshadow-y line is "I'm invisible. I'm turning into you. It's like a horrible dream." Helpfully demonstrated with gifs
Not to mention all of the inverted parallels this movie did comparing to scenes in TFA. Bucky and Steve standing across from each other in the helicarrier like they did in the Hydra factory, Steve falling from the helicarrier as Bucky watches vs Bucky falling from the train as Steve watches... Steve volunteering and being assisted out of that super-soldier-making machine vs Bucky being forced and strapped down. These movies really care a lot about symmetry and symbolism and it's perfect to me. We're going to have an amazingly cohesive trilogy once we've gotten around to Ca3.
Also, I noticed there was a scene with Cap checking the field after a battle and there was a Hydra soldier lurking, Bucky shots the guy from afar, that was very much one of TWS specialties.
The writers said, they did a lot of foreshadow for Cap2, in hope that they could write that storyline for the next film.
The other great aspect of Cap2 is that in a non obvious way, they addressed several things from all the other movies in the MCU and did a good wrap up of those things too.