I enjoyed that have watched it twice twice now,
Now for wild speculation my thinking is that the doctor. Will take cyber bill and rebuild her/it as nando
And bill is the new doctor, I am sure moffat has said before he wanted more Diversity in the show. He would get the credit for doing it and as he is pissing off would not have to deal with any fallout from fans.
Then the next doctor will be traveling with her self bill doctor and cyberbill modefied into nando. This means the Christmas special will be
A double bill