I can't understand that either. Enough of her remains have been located for DNA testing to determine positively that she is deceased. It is doubtful that all of her remains will ever be recovered. However, a post earlier in this thread said her status will not be changed to found to Found Deceased and the thread moved to Located, until all of her remains have been found.
This is similar to the case of Alexis Gabe. Alexis was positively determined to be deceased from DNA testing of the partial remains that were found. It is unlikely that all of her remains will ever be located. In her case, her thread was moved to Located, Found Deceased. I can't understand why the same wasn't done in Beth's case.
Edited to add: Now that he husband has been sentenced for her murder, the thread will probably be marked Guilty and moved.