We will Chronicles: Volume 2 or whatever for that!
Its entirely possible that Azeroth was the last in line for creation, so all the old Titans are all "Allright, time to take a break and have all these baby Titans create the next generation". Or whatever.
Still, its good to get some qualification on this subject, even IF it disproves some theories here. (We now know, for instance, that Ra-den and the Mogu definitely were NOT the ones responsible for Y'Shaarj's demise)