While DC definitely have their plans, we already know that they change their plans to accommodate for general interest and sales. Didn't Tynion complain about the plans changing constantly, and that was on his flagship book?
DC created Wallace West to replace Wally and then took it back once the fans didn't accept him. They abandoned the entire "new 52" once it was no longer profitable and created Rebirth.
Right now characters like Steph, Cass, and Wally who were abandoned for years are now back. Wally is the main Flash, Cass and Steph are the main Batgirls.
So it's entirely possible that if Jace flops or if the new league won't sell, we'll see Dick there. Or that he'll play some part in mentoring the new league. He's already Damian's mentor, and he's likely going to be Jon's mentor as well.