Hate that term. Surely stories appealing to the fans is a good thing? Pretty pointless to write stories the core audience don't like, one would have thought.
Why exactly do you consider last week's episode "fanwank"? I and the Missus enjoyed them immensely, not knowing all the previous speculation in fandom about transgender regens and conscious TARDISes (TARDISii?).
Just because fans have written about such things doesn't make them "fanwank". Nor neccessarily would an enemy origin story for the Autons or whoever (can't see it for this episode). Unless you personally don't like them, in which case it's an extremely derogative way of expressing that.
Not having a go, just would appreciate you being more constructive in your critical observations, I've seen your previous posts, I know you are capable of more than the term "fanwank".