Does a thing sorta car-shaped without wheels count as a car? This thing never even had a lid. (You could call it a car, I guess... Rectangular, and you can sit in it.)
Many people hope a legitimate sarcophagus, with an actual mummy in, might yet be found.
At which point of building a car separate parts become a car? And during maintenance (lets say engine replacement) is a car still a car? I'd say it is if meant to be used as a car again.
Right. So, is a stone box in a pyramid chamber that there is no evidence ever held a corpse, or even had a lid, and certainly will not have a corpse in the future, really a sarcophagus? It seems to depend on overconfident assumptions.
Given their experience, a decoy that looks like a looted tomb would just be good planning.
Of course it's a tomb. You have the mortuary temple out in front of it, with texts telling you exactly what it is. It fits in stylistically with mastabas, step pyramids, and true pyramids that come before and after that are unquestionably tombs.
Old Kingdom mummies don't tend to survive, probably due to a combination of their extreme age, the still-developing mummification process, how uncommon mummification was in that period, and that mummified bodies were targets for looting given the precious objects that could be found on them and in their wrappings. That a sarcophagus is empty that has been open since time immemorial in a tomb that has been known to be looted in antiquity is utterly unsurprising.