Itachi wasn't supposed to be pleased, Itachi was a patient. Kabuto carries him along without complaint, using it as an opportunity to continue to analyze him with his own Chakra as they walk. "As expected of Orochimaru-sama," he says after a moment, studying the area. "Also, Uchiha-san, I would request you not use Amaterasu in a confined space such as this unless you relish the idea of me removing the eye that is responsible for your own safety."