I ask this with my tongue partially planted in my cheek: If a person, recognized as especially knowledgeable in a field, makes an edit to a article in that field, then cites their own texts as sources, would this be acceptable to the Project? Do you see what I¹m getting at? Who would Einstein have cited?
If they are citing published, peer reviewed texts then that's what matters, who wrote them is irrelevant. If they cite just the fact that they are an expert, that is not acceptable.