It seems to be in a state of flux.
What does that mean?
I don’t know. It’s the sort of thing the Doctor would say!
You need a good death. Without death, there’d only be comedies. Dying gives us size.
What made River’s exit/goodbye even more depressing is that she was the last living thing that was linked to Amy and Rory. River Song is The Doctor’s last real connection to the Ponds. And now they’re all gone.