I have a drunken theory... after Infinity War we follow Black Widow into a room with Captain America and Nick Fury. They're talking to a hooded figure. The hooded figure says "Death has ressurected her greatest champion... only the Avengers can stop him!" He turns to the camera and it's Luke Skywalker and the next Avengers movie they fight Darth Vader.
Would be terrible and amazing at the same time. Would probably be the greatest thing that ever was. Just for the online shitstorm.
I just want Captain America to be Luke's real dad.
Star Wars episode 9 : The Last Bucky.