5. A Doctor By Any Other Name
There's no denying that retconning the Doctor's timeline to shoehorn in the War Doctor was a bit forced, since he openly admits to having had no choice but committing double-genocide and destroying his home planet, even while refusing to acknowledge the incarnation that did it. There has to be more of a reason to disown the War Doctor, we have to see what atrocities he committed to understand why later Doctors are only willing to give their name to his final one. The War Doctor seemed to be hopeless and exhausted by the time we saw him, not the callous warrior that he seemed to be regarded as. Since Rassilon refers to him as the Doctor when learning that he's stolen the Moment, perhaps this action was the first Doctor-like thing this incarnation had done, ending the insanity of the War and himself rather than continue to be an aggressor. Later incarnations recognise that he had no choice in destroying Gallifrey (even willing to do it again in The Day of the Doctor
), but it's everything leading up to that point they can't forgive. Moreover, if he's renounced the name of the Doctor, what does he go by now? The obvious answer is that he reassumed his birth name, the one that he abandoned when he first fled Gallifrey, and performed the heinous acts he's credited with under that name. However, the mystery of the Doctor's name is one that the franchise will never truly explore, since it's much more effective than to give him some moniker with only in-universe significance. It's likely this will be a mere technicality and the narrator (we don't yet know from whose perspective the novels will be told) will refer to him as the Doctor for simplicity's sake, but it may still be worth exploring.