I've long said that there will never be a better time to put Hartnell up for order than the anniversary year. Doing so on the actual anniversary date would probably be about as perfect as it gets.
I also strongly suspect that An Unearthly Child will get a UK tv airing on that date as well.
William Hartnell was luckier than many during the great BBC purge, and actually still has 17 complete stories available, plus one other that was completed via animation, and at least one other that might be completed with animation in the future.
Poor Patrick Troughton only has 6 complete stories available, plus one other that was completed via animation, and possible at least one other that might be completed with animation in the future.
To me, the loss of so much of Troughton's era is the bigger tragedy, just because with Hartnell we still have all but one story from his first season (if you count Reign of Terror being completed with animation), all but one story from his second season (and that one, The Crusade, could potentially be animated in the future, as doing so would apparently fall within current budgetary parameters), we've only got three out of ten in his third season (however the ones we get at least ensure we get to meet all of his regular companions), and he only did two stories in his last year, the second of which still has three out of the four episodes, and is a prime candidate for reconstruction prior to release. So with Hartnell we at least get a feel for his entire run on the show.
The Troughton era on the other hand was nowhere near as lucky, and he has no surviving complete stories from the seven in his first year, only one complete story from his second year (and another that may be completed by animation) out of the seven made, and then a whopping six out of seven of his final season (one of which was completed via animation), so we don't get much of a feeling for his second year, and outside of audio or orphaned episodes, no glimpse at his first year at all, so most of what fans know of Troughton comes from his final year, and his return appearances in the Three Doctors, Five Doctors, and Two Doctors stories.
Still makes me sad.