That's kind of my take on the question. Eventually you would have a clone of Findagrave. I could certainly see the benefit of a Category:Cemetery.
For example: Bethel Cemetery, Hymera, Sullivan County, Indiana, USA. I would like to associate the person with the cemetery, but also have the person show up also in e.g., Category:Hymera, Indiana.
I'm not sure how that could be done nicely.