Board Thread:Theories and Speculation/@comment-30241447-20170503042327/@comment-4961229-20170510153135

Itachi knew full well that Akatsuki was assembling the tailed beasts, whether or not he was privy to the final plan. He was told about current events when he was revived. If he somehow could seal the Juubi and didn't even make the attempt, he is the most derelict character in the series. Since we know he's devoted to Konoha, he apparently didn't think this was possible.