Well, here's the thing. At least one person who was on the virtual floor of the NYSE when Jormungand hatched survived (namely Puck, and Dodger, if he was there), and others who were thought dead have proven to be still around, somewhere (such as Pax). The big three AIs were all infinitely more powerful than those two, so without a 'body' or some other means of confirming their destruction, there is plenty of room for the possibility that the AIs are still 'alive', though perhaps in diminished capacity, or locked in some Resonance Realm. Add to that the fact that their source code should be somewhere in the Endless Archive...
Ooh, I got a story idea...