As a consequence of their religious beliefs, the ancient Egyptians had great reverence for their ancestors and would go to quite extraordinary lengths to protect their long dead bodies, often removing them from their original tombs to new, safer tomb locations when it seemed their original tomb was in danger of some kind (usually from tomb raiders).

So it would not be at all surprising to find that the AEs, in believing that their entire kingdom was in peril from a future deluge that would destroy the entire country (as stated in the Coptic / Arabic texts), would take this precaution of re-burying their ancestor kings in a massive chamber in the heart of the Great Pyramid--a way to preserve them for all time and, specifically, from the destruction of the coming deluge.

I fully anticipate that there will be no access tunnels anywhere to this chamber. I suspect the bodies of the ancestors would have been lowered into this 'burial vault' when the roof of the vault was still open providing the only access to the cavity and sealed over as the pyramid was built upwards.

Some years ago it was proposed (I think by Lehner though not 100% sure) that the numerous slots or niches we find that run the length of both 'pavements' of the Grand Gallery were to hold statues of Khufu's ancestors. If this newly discovered void or vault above the Grand Gallery really does contain the actual bodies of these ancestors then this would make perfect sense as each of the ancestor statues believed by some to have once stood in the Grand Gallery would have effectively served as a Ka double for each body of the anestor kings in the hidden vault above. Indeed, by counting the number of these slots in the 2 'pavements' of the Grand Gallery, we may have an idea of how many ancestor kings may have been interred in the hidden vault above: 27 pairs = 54 ka statues = 54 ancestor kings perhaps residing in this hidden space.

SC