No, Buddha did not preach True Self (atta, atman) in disguise as anatta.
I often come across people who claim that Buddha was just rehashing Hindu teachings in a weird way. But this is due to a flawed mode of inquiry . Buddha actually preached (as in MN 38 ) the opposite of Advaita/True Self/Universal Mind/Ground of Being/Divine Source, but if you have not gone beyond the Advaita realization yet, then there is no way for you to understand it. Most practitioners, including even some Buddhist "masters" (mostly Mahayana ones) have fallen into the Advaita trap of True Self (Atman) and think that is what Buddha meant by anatta. I originally also was in that trap, but thankfully after studying Thusness Six Stages of Awakening and the Bahiya Sutta , and speaking with Soh Wei Yu of awakeningtoreality.blogspot.com , I managed to get past the Universal Mind stage and dissolve into actual nibbana (as it is described in Bahiya Sutta). Nibbana is infinitely disjoint--total opposite of One Mind/Cosmic Consciousness. Imagine if you will every single atom/flow o...