I agree with Keith. Everything on a profile should have a source. In the case of categories, there should be sufficient evidence in the bio to support the category. For example Place categories should say what happened in that place and that event should have a source.
U.S. President Direct Descendant category standing alone bothers me, because usually there is no source listed, and frequently we don't have a clue who the president is either.
Ideally, I think, that categories should be added after biographies, with sources.