I know I'm being clouded by my bias and my love for her, but I can see a scenario where Daisy Ridley could become an A-lister. She's the only new actor from the ST who is getting big material from major studios with Orient Express, Peter Rabbit, and maybe the new Liman joint. With a few more strong non-Star Wars movies, she could be the Harrison Ford of the group.
Adam Driver and Oscar Isaac are also working with every indie/prestige director under the sun, so they'll probably get some solid work over the next few years, although I do see Driver getting better opportunities.
Not really super confident in Boyega just yet, but he can probably carve out his own niche like Mark Hamill has.