I feel like it'll be a case where All Might does die, but manages to get revived by someone or something. It being one of those loop holes, where he does die as predicted, with the twist that he managed to come back.
I lean on the side that I don't like series killing off main characters, especially since most of the time it's only for shock value.
That said, because of the constant back and forth, such as with the Todoroki family, and Bakugo, then Uraraka (In her case, I honestly would quit reading this series if she died).
So because of all that back and forth, we probably should have All Might die. That said depending on how it's handled I think it'd be better to have him survive. All Might's doom is something that's been hanging over our heads all this time, so I feel like it would make this whole exchange between him and AfO entirely predictable, since "he's predestined to die". I'm fully expecting AM and AfO having a back and forth, with AfO being the victor, but Stain appearing before he can kill AM, fighting AfO himself, and likely dying instead of AM.