I'm just going to point out that you need a fair number of survivors all in one place to have a viable gene pool for the continuation of a species. I'm not averse to the notion of a few getting away from the shivans' wrath, but the surviving ancients, and their freakishly inbred spawn have had a few millenia to die off. Frankly, the universe and the game series are probably better off for it, as you probably don't want to hear a round of ancients monologues that culminate in the vile, defective, final offspring of the race choking to death on its own spittle because it lacks the mental faculties to swallow.
Let dead races lie.
That much is true, but we are talking about a race that was capable of conquering more systems than the GTVA have discovered. 10,000 people is only a couple of Destroyers' worth, after all, you could probably fit that onto a single transport in evac conditions.
Considering you could fit around 3 Billion people onto the surface of the Isle of Wight, it's not really that vast a number to be beyond possibility. As for rising again, not neccesarily, take a look at the Native Americans, they changed from voracious hunter-gatherers into a society with incredibly deep respect for the environment, that change in mindset was bought about by an ecological disaster, which was itself bought about by a new kind of spearhead. Traumatic events can change a society at a level in that respect, and simply because the Ancients may have survived biologically, there's no reason they had to survive technologically. This is, of course, assuming that the Ancients required a gene pool similar to humans, some Earth animals can rebuild as a perfectly strong species on far less.
Now, I'll admit, the chances are high that the Ancients are extinct, but even if they did survive, there's a distict possiblity even
they wouldn't know they were the ancients.