Since Chris Evans is known as Captain America, he will probably Captain America again if there is another movie made about the superhero. If not, then obviously he would not. However, I do believe as long as people are interested in Captain America. The job will be given to Chris Evans because fans like to see the same actor play the same characters.
This has been the way in which many sequels with both superhero movies and those without. After a popular movie is made, a sequel and another sequel will be made to make money. Since the producers don’t want to change something that went so well, they will try to include the same actors to play their original parts.