Ultimately, altruism and egoism are the same thing. Every selfish act can be reframed as a selfless one and vice versa. If it can’t then it’s actually an act of shortsightedness.
Where do you get the idea that he is arguing about selfishness? What I see is an argument that it is possible to care about things that you won’t experience. As long as you believe that something might be(come) the case you can have preferences related to it. Regardless of wether or not somebody calls your preference selfish.
Ultimately, altruism and egoism are the same thing. Every selfish act can be reframed as a selfless one and vice versa. If it can’t then it’s actually an act of shortsightedness.
Therefore, you are answering a wrong question.
Where do you get the idea that he is arguing about selfishness? What I see is an argument that it is possible to care about things that you won’t experience. As long as you believe that something might be(come) the case you can have preferences related to it. Regardless of wether or not somebody calls your preference selfish.