One of the first things that happens in the titles is that we are whisked through a graveyard. While a graveyard is a very, very subtle metaphor for death, it could symbolize any character's death. How do we know it's going to be M, rather than "Nameless James Bond Girlfriend #3"? The camera is moving fast, so it can be hard to spot, but for those who catch it, it's clear as day: The words "and Judi Dench as M" appear right in the middle of the screen as the camera pushes in on a gravestone. For a moment, it clearly looks like an epitaph (albeit a very reductive one for Judi Dench).
Heaven is not having to be in Spectre.
We then swoop to a CGI Skyfall as Adele's prophetic crooning lays out the plot like she's recording the Skyfall audio book:
Let the sky fall
When it crumbles
We will stand tall
Face it all together
Skyfall is where we start ...