I just had a thought brought on by this post which says that Clara is the Doctor’s answer;
So we know “Boy and girl fall in love, get separated by events - war, politics, accidents in time. she’s thrown out of the hex or he’s thrown into it. since then they’ve been yearning for each other across time and space - across dimensions - this isn’t a ghost story, it’s a… love story.” is the oldest story in the universe. And it basically translates straight to “the Doctor and Clara are a love story”
Then in the Christmas special we have the oldest question in the universe. Clara replies to, “Doctor who?” by telling them that all the name he needs is the Doctor. “And if you love him, and you should … help him.”
The oldest story = The oldest answer
Since we now know that Clara told him what would become the promise he makes by becoming the Doctor; maybe what Clara told the Timelords was exactly what they wanted to hear?