If there are references of the Harry Potter films in Stranger things, and we all know about the theorie that Will is like Harry he has a part of Vecna in him and Will is the one who has to kill Vecna, or at least, he has a really important part with it. (I mean, I saw that Eleven might be Neville and Will Harry. I say this bc of Trelawney's prophecy, about the chosen one).
And I got to a conclusion that maybe Will dies. But hear me out, he is not fully dying. Like, why they showed us that Eleven suddenly can bring someone back to life? Or she is powerful enough in that aspect.
Will needs to kill that part of him that is connected to Vecna, and I think that's why Will is going to die, but Eleven is going to bring him back to life.
I mean, it's just a theorie that came to my mind (I'm rewatching Harry Potter xD). But it wouldn't be so crazy? Idk