Where Do You Think The Kages Are?
If you read the latest Naruto chapter, you would know that Sakura summoned Katsuyu. Here is an excerpt from the Naruto bible (Narutowikia):
"It is also shown that summon animals can also choose when they can be summoned. In the event that they're busy with something, they can't be summoned, however they can have a substitute enter in their stead"
-This means that Katsuyu was DONE healing the Kages, because Sakura was able to summon her, which means she was no longer busy.
-Katsuyu did not even mention the Kages or seemed alarmed at being summoned, which means that she healed the Kages.
-If the Kages have been healed... where do you think they are? Shouldn't they have been on the field by now?
-Orochimaru only mentioned Tsunade... he didn't mention anything about the other Kage or their condition, which makes me believe that they left already. If that is the case, would they really leave Tsunade to die? Don't think they would.