10 MCU Loose Ends That Will Mean Something In Phase 4

4. The Winter Soldier's Past

Just as Scarlet Witch's past can't simply be tied up with a bow and forgotten about, neither can Bucky's. Even after he was reprogrammed by Shuri in Wakanda, he still has some SERIOUS skeletons in his closet and it's not enough to simply say that he's cured and everything is finished with.

That's certainly not what Zemo is going to do now that he's been confirmed as the villain for The Falcon & The Winter Soldier (which perhaps explains why the series refers to him as his "dead name"). His return suggests that we're going to see a continuation of the friction between Bucky and Zemo, probably inspired by the latter's disgust that superheroes continue to not be accountable at all for their actions.

The Russos have hinted that Bucky remains volatile - which is why he wasn't chosen as the new Cap - and him having to deal with all of the targets he took out over the years as an assassin after the point of him healing is a very interesting position.