And my thoughts...very similar to Nick's.
All of time, Time past, Time present and Time future all exist and co-exist on both a linear path and a non-linear path to infinitum. To those beings who exist on a linear path, once the moment has past, it can never be recaptured and only what is now and what lies ahead can be captured.
To a time traveler, there is both a linear path and a non-linear path. Linear would be personal, as in his life time, regardless of to what point he travels, the days of his personal life and time stream are linear and move forward. (If he goes to 1562 on Monday, 1789 on Tuesday, 5631 on Wednesday, he will still personally be 3 days older on Thursday than he was on Monday)
The non-linear path is his ability to travel in time, so that which has happened in the past, is still happeneing and he access it. What hasn't happened yet is also happening and he can access it.
Except the time war!
Since it was time locked, he cannot go into it to prevent it, nor can he now go back to ANY point in Gallifrey's history as it is ALL unaccessable to him. What would stop him from going back to the time of Omega and spelling it all out for him in order to prevent it?
So, the war on Gallifrey, and for that matter all of Gallifrey's history did happen, and is currently running in the same non-linear time stream, however he cannot access it, so it is, in effect, dead! On Gallifrey there is no history past the Time War, as that was when their point in time died and to the universe going forward, they are gone!
To explain further, we know that at one time Dodo birds were on the earth. We could go back in time to visit and see them, but at the point of their extinction we have a stopping point. If we want to see one, we are limited to the time that we can go back to and see them, yet for all intents and purposes, they are still alive and well in that non-linear stream.
Confused? me too.....
But thanks for reading anyway!
This question requires you get into some of the basics of time travel science.
In short: All time coexists, just as all space coexists. Even though we are constantly experiencing time in the "now" that does not mean previous nows don't also still exist even though we can't experience them anymore. It's the same way that a room in your house doesn't cease to exist simply because you locked the door to it and can no longer get in.
Now, because Timelords are time travelers, if the planet had simply been "burned" or destroyed as previous Doctors have mentioned, then there would be nothing to prevent one or all of the Timelords from traveling forward in time to a point after the end of the war and surviving. Since Daleks have the ability to time jump as well, they could then do the same, and the war would rage on, destroying the universe further. The only solution then is to take the series of events (The specific "nows") that make up the Time War and put a sort of fence around them so those within them can no longer get out to try to affect the outcome. This is what the time lock is.
The first shots of the Time War dictate the beginning of the time lock and the moment that Gallifrey ceases to be in this universe (Whether through The Moment or through the Doctors' intervention) dictates the end of the time lock...a fence that contains all of the events. This means that Timelords from the old series, if they happened to be galavanting through space couldn't "accidentally" find the Time War and use their time traveling to try to affect that, they'd simply be unable to access it.
So to answer your question: it's both! The Time War still rages on inside the time lock, even though the planet seems to have been successfully retained in a pocket universe since time is all concurrent, it's only perception that is linear.
...That is the simplest that can really be without really delving into the ideas of directionality/flow in space-time.
-Nick
