It seems that the 9th Doctor felt that the departure of Steven Moffat from Doctor Who was a good occasion to spread some good will. According to those who attended the final wrap party for Peter Capaldi and Steven Moffat's final Doctor Who episode, a special message of congrats was sent via video from former Time Lord, Christopher Eccleston. Is all the bad blood between Eccleston and Doctor Who finally in the past?
On July 8, one of the attendees of the wrap party, Edward Russell, tweeted that the best part of the festivities was a special message from the Eccleston to Moffat. This means that Christopher Eccleston — famous for his caginess about being on Doctor Who for only one season — went out of his way to congratulate Moffat. While the exact contents of this video message are unknown, it did lead some fans to speculate that the 9th Doctor might somehow make an appearance in the upcoming Christmas episode. Previously, Steven Moffat has admitted that he originally intended to have Christopher Eccleston return to the role in 2013's "Day of the Doctor," but was unable to do so because of scheduling. Could something have changed? With Peter Capaldi's 12th Doctor visiting the 1st Doctor, could the 9th Doctor show up too?
Realistically, Eccleston's message of congrats was probably exactly what it sounds like, and not a hint that he is returning to don his Time Lord leather jacket again. Back in May, Eccleston told Inverse (probably jokingly) that he would return to Doctor Who for the "100th anniversary."