What role will Kyle and Aiden play in the future of humanity?

I ask this more than anything because I have quite a few doubts about the future of these protagonists and it is known that the main plot in the future will be to find the definitive cure, but since it could be done with both characters, will it be like Marvel Spiderman 2? Or like the last of us 2? I liked both characters but I don't know what they will do with them because Aiden is definitely not going to disappear and Crane still has a lot to give.