I’m curious as to who complained about this and how the investigation got started—although I doubt we’ll ever find out.
I also would have said that, as in the case of Holocaust victims mentioned in the article, Mormons have pretty commonly baptized just about everyone they can find records of. The vast extent of Mormon genealogical records is famous.
I suspect if they had, and it was made public, the reaction would be...interesting. in the extreme.
At this time the only one who can do temple work for a Holocaust victim is a direct descendant such as a son or daughter who is a member of the LDS church.