The return to Thebes was, at first, a gradual process with the old gods gradually coming back to the fore, and for a while coexisting with the Amarna Atenist faith.
During the reign of Akhenaten's successor Smenkhkare there is no evidence of any sweeping changes. During this period the child Tutankhamun probably still enjoyed life in Akhetaten, as the Aten would have been virtually the only god he had known.
There is evidence that, for a time at least, the old and new religions lived side by side. It is well documented that Tutankhaten changed his name to Tutankhamun, but objects from his tomb show that, at least for a while, both names were used. Indeed the royal crook which was the symbol of the Pharaohs power has the name Tutankhaten on its end.
As the court drifted away from Amarna back to the traditional capital at Thebes, there is evidence that Tutankhamun was involved in the restoration of the temple at Karnak. The 'restoration stele' there records Tutankhamun's reintroduction of the gods Akhenaten had turned his back on.
In these early days there is no sign of active suppression of the Aten and the Amarna legacy. The cult of Amun began to gain prominence again throughout Egypt, but it was not until much later, with the death of Ay, that the active destruction of the memory of Akhenaten and his bloodline began.