That's very believeable and it could happen. But I personally think the only reason Zetsu showed up was because the kages were about to form a 5 country alliance against Akatsuki. Madara probably freaked about this and told Zetsu to go tell them Sasuke was near by. This way all the Kage's go into Chaos trying to find him which breaks up the meeting, and the alliance never gets made. And if so ... then Madara really isn't trying to betray Sasuke. XD Thoughts?
ok i hαve α random prediction. Zetsu could just be α diversion for Sαsuke or Mαdαrα to sneak in. everyone will be focused on Zetsu since one of the first things he sαid wαs he knew where Sαsuke is αnd it'll start α riot. the Rαikαge might even try to αttαck him-but his guαrds will prolly hold him bαck if he does-αnd he'll most likely threαten him. i'm thinking most of the Kαges will be spitting out questions αt him and Zetsu will stαnd there doin his job; looking evil.. i don't think αnyone will αttαck either, becαuse he's the closest source of informαtion they've got. [αnd they know he's pαrt of Akα so who in they're right mind would αttαck? xD] thoughts?
p.s. Madara probably found out about this since one half of Zetsu is monitoring the meeting while the other half is with Madara. And I'm guessing the two halves can communicate with eachother.