Sounds like after reading the article that it’s a case of we know best.
Not knowing the fine details of the original search you could take the view that the police don’t want to be proven to have missed finding her in the first place.
Understandable this is the final effort to locate her remains. However, given the post above about the pig farm there may be nothing to find.
I can’t honestly see the remaining brother putting his hand up and saying that they fed her to the pigs.
I sincerely hope they do find her remains, her family deserves this after all this time.