Yes, but their characters aren't that important to the overall story. Siuan is barely mentioned in book 1 and only becomes a minor part much much later. As the books continuously point out: all the Aes Sedai scheming is all for naught anway. So why waste precious time on side stuff when we haven't even established the key characters yet. As Ouchi eludes to, most people don't even know the MAIN characters yet.
This is supposed to be a story about the Dragon Reborn and how each of his friends are sucked into being ta'veren. Not about Morraine, Warders, and the White tower. Right now she's utterly dominating screen time (1:28 for Morraine and the next closest goes to 1:02 for Rand). That is going too far off the beaten path of the book, which was 100% Rand.
Obviously, as we approach the Eye of the World, things should shift.