Opinionated (and others defending Trump's campaign on this)

The Arlington National Cemetery rules that apply here are specific to using photos, videos for political purposes, here's an excerpt from the link below:

“Federal law prohibits political campaign or election-related activities within Army National Military Cemeteries, to include photographers, content creators or any other persons attending for purposes or in direct support of a partisan political candidate’s campaign,” the cemetery said in a statement.

It would not apply to ceremonies, burials, etc... unless it was used for political purposes

https://thehill.com/policy/defense/4852429-what-arlington-national-cemetery-rules-say-about-politicizing-grounds/