It's a small contingent of it, there's still quite a bit in orbit fighting with the latest fleet (what was seen in the Fall of Reach novel). HiGHCOM is basically Reach's military brain so it was definitely something worth protecting.
Love the final image of the ships coming to the rescue. Wonder how the hell they all hid from the Covenant for so long as Reach was being torched? Plus, what's that class of ship in the bottom left panel? I keep thinking Babylon 5's warlock class dreadnought. I suppose I should just go downstairs and grab the damn Halo Universe book to look it up but I'm feeling lazy before work.
In regards to the ships surviving this long, I figured since the ground battle is still happening in the game at this point in the timeline, there must still be something left of the fleet to hold off the Covenant from utter destruction. And if you look back at the older Fall of Reach novel, the space battle the Pillar of Autumn took place in was happening at the exact moment.
Nice. Went and re-read the ship bit from the Encyclopedia and figured it must have been some type of destroyer class (mostly as it was the only class besides the biggest class that didn't have a picture). I can actually guess things once in a while. Yay!
Also, thanks for steering me in the direction of that animated comic. Was a good story!