Well, you’ve sort of answered your own question. Your take on indigenous spirits whisking them away is countered by about a dozen other interpretations, the mystery with it all being that the author of the book created a final chapter that explains what happens, but it was never released and she’s never disclosed.Seen the original 1975 a few times but never really understood this film. Bit of a bore in fact as most of us were brainwashed believing it was a true story. Just a fantasy based on indigenous spirits more than anything else.
Also, like most popular novels, there’s another bunch of interpretations as to the meaning, themes etc of the book and what the author was trying to convey.
The movie itself is considered a bit of a masterpiece as well for its cinematography, music, acting yadda yadda yadda.