The problem here is that Timelords did exist and could travel in time and they were able to have multiple versions of themselves existing in the same space and time.
Now if a time travelling race was once able to do something then obviously it always was and always will be able to do it. Even if the destruction of Gallifrey make sit impossible for this to ever occur again after that reference point there’s no problem with it having occurred prior to that event and the villain/s travelling forwards in time to the present.
So the idea makes perfect sense. And would have been brilliant.
Except that that brings up the question of how the Gallifreyans kept time travel from interfering with their own history. Reading between the lines, I’d always assumed that Gallifrey and the Time Lords ran on a sort of “quasi-absolute” time: with the rarest of exceptions, they never got “out of synch” with each other. I remember an episode with the fifth (Peter Davidson) Doctor in which he and his companions accidently ended up in the very far future and the Doctor was extremely anxious that no one ever find out that he’d been in that time period. I wonder if he had illegally gone into the relative-to-Gallifrey future.
I asked a far more learned Whovian than myself the question of timetravel and the history of Gallifrey. He told me (he probably cited episodes and novels) that Gallifrey itself was protected by a chronaton screen or something similar. That would explain why the Master, the Rani, etc were constantly tampering with the history of other planets in order to gain power, but never did the same with Galifrey.
Sorry to continue the Whovian hijack, but, how were the Time Lords wiped out? I have not seen the episodes in question where that is revealed (and I don’t mind spoilers for that plot point).
They are freakin’ time travellers. They are not all going to be in the ‘present’ whenever a given attack occurs. And they have the ultimate defense: “If we’re losing, hop back in time and we’ll reinforce our fatal flaw.” They don’t even have the biggest problem facing a time traveller going to the past to warn of impending doom: people disbelieving you and your crazy talk.
And given The Doctor’s adventures, at least some Time Lords enjoy mucking about and altering the hell out of other species past/futures, you might think someone is going to stop in at the presumed ruins of Gallifrey and head back to stop it. The extinction of your own species would sway many folks’ general principles. Perhaps that’s just for an, as yet unfilmed, episode’s Doctor to make happen.
Also, I concur that multiple iterations of a Who-universe villian would be potentially brilliant, given the Who-reality’s unique take on the aging process. (And what a novel sloution for a TV show to have built-in to explain the inevitable actor swap over a long term run.)
Speaking of unfinished “Doctor Who” stories, it’s an odd bit of trivia for sure but the brit sitcom Are You Being Served? was actually inspired by a never-filmed serial from the William Hartnell years. Apparently the first Doctor, Susan, Barbara & Ian were going to visit a planet-sized department store run by a race of evil aliens!
Back to the original subject: After H.P. Lovecraft’s death, several scraps of never-completed stories were found among his papers. A few of the scraps have been printed as is, including “Azathoth” which would have dealt with the oft-referred to ‘mad idiot god at the center of the universe.’
Chris Claremont also has remarked that he intended to write a year-long X-Men storyline in which Wolverine would be abducted by the league of assassins known as the Hand, brainwashed into serving them, and consequently become a villain that the X-Men would be forced to fight. The Powers That Be at Marvel nixed the idea (perhaps because it was too much like the Dark Phoenix storyline.)
During the 1990s, the then-X-writers (can’t remember their names) proposed a story in which Magneto altered the world’s magnetic field so that weather went bezerk on a global level. Storm would sacrifice her own life in order to restore order. Again, the PTB at Marvel said “no way!”