That is a new one on me. I actually lived on FT Hamilton as a member of the military in the late 90’s and worked there after 9/11. You usually have to have a nexus with the DoD in order to get on the waitlist.
As a DoD federal employee one could, or as the dependent of someone who has that DoD nexus. I think there is more to this than just the waitlist. Does he have someone in his direct family who works for a Federal Agency or the DoD?
That would be a heck of a question to ask him.
I live near Aberdeen Proving Grounds in Maryland. Some civilians live on post, but as far as I know, they also work there. A friend married a girl from India and because she isn’t a citizen, he had to move off post.