I’m thinking like Seaprincess here and it’s likely the property owner requested removal, which isn’t uncommon for a cemetery. They may have also asked that other Wayspots and nearby Power Spots close by be removed out of respect.
Being there are veterns buried here and there is a class action lawsuit in progress for some of those resting here, I wouldn’t be surprised if this falls under the controversial sensitive location. While this isn’t any of what is mentioned, some may believe that these vets were oppressed in a way.
There is also a note to consider legal issues, since we are to play the games lawfully, and there could be some legal issues for people visiting here.
You can read the full clarification here: Cemeteries & Other Sensitive Locations
And if you’re interested, there’s a web form for property owners/managers to use to request removal of stops/gyms: Request modification or removal of a PokéStop or Gym – Pokémon GO