He was written out. The later king lists jump from Amenhotep III to Horemheb, treating the whole Amarna sequence as a gap, and by the Ramesside period he was not part of the official past at all. That erasure is probably why the tomb survived. It is small, it is low, it lies off the main axis of the Valley of the Kings, and the debris of later tomb cutting covered its entrance, so although it had been entered and partly robbed in antiquity it was never emptied.
What Howard Carter found in 1922 was therefore the only substantially intact royal burial of the New Kingdom, and almost everything the modern public pictures when it thinks of Egyptian funerary religion comes from it: the nested gilded shrines, one of them carrying the text of the Book of the Heavenly Cow, the canopic chest and its miniature coffins, the shabtis, the amulets laid in the wrappings, the gold mask. Two mummified foetuses were buried with him. The atlas records the obvious caution that goes with this. A single burial of a young king who died unexpectedly, in a reused and undersized tomb, is not a representative sample of anything, and the enormous influence of the find rests on an accident of preservation. The story of a curse on those who opened it was a newspaper invention of the following months.