Leaving aside the pettiness of trying to have a name removed because one doesn’t like the placement of it, what legal recourse would the survivors have? The names of the dead are public record and I would assume they are not trademarked (and even if they were listing the trademarked name among a list of the other dead would not seem to me to be infringing on the trademark). Presumably the caretakers of the memorial would abide by the wishes of the families in not including a name, but if they chose not to what could the survivors do about it?
The names are in the public domain. No permission is needed from the survivors’ families for their use in the memorial. If it were a commercial venture, that might be a different story.