Responses

I think it’s likely a reference to the advancements in modern technology and medicine. Men have been able to “give birth” even currently, so it seems very possible that with enough time they would find a way to break their immortality.
Seems sad, but lord knows they would have lived very long and happy lives together!
As much as I want a spin-off, I do not want them to see watching each other die so let's leave at that. I love them so much ( ノД`)…
And yes, they died. Just noticed the hand of a child in that last chapter. They actually found a way to break the curse of immortality. As to how and where did that child come from, let's leave that in our own imagination :))