And I had forgotten about the Doctor's speech on how time can be unwritten.

Time can be unwritten. ... It's been happening all around me and I haven't even noticed. ... The cyber-king. A giant cyberman walks over all of Victorian London and no one even remembers.

And when I was trying to get out of writing that down while starting and stopping the video by googling it, I found out a) that nobody has written it out in all of the internets and b) a theory that the Doctor is being unwritten.

I like our theory better.

There is one thing, though. The unwriting of the cyberking and the daleks, that fits with our understanding of the world, how we remember history. So that should not be reversed in any way. It seems like Moffat's way of cleaning up after the mess left by Davies. It might still be possible for Amy to remember Rory, though. But everything cannot be put "right".