At least with human endocannibalism, the bones are burned, buried, or kept as souvenirs.
What makes endocannibalism a somewhat attractive hypothesis to me vis a vis Sasquatch, is that it would be a lot easier to bury a bare, disarticulated skeleton than it would be to bury a 9 foot, 700 pound body. Imagine trying to bury a cow or a horse without hand tools, much less without a backhoe. Of course, one can pile rocks or debris over a body and bury it, but that leaves quite a landmark to be discovered by humans. And the problem I find with cave entombment of Sasquatch remains, is that practically every cavern that is big enough to drag a full size Sasquatch into has been well traveled by man with no Sasquatch remains to show for it.
In the end, it's all conjecture that tries to explain a lack of remains. Burial, with or without endocannibalism, is a rational hypothesis.