The
RAE article about leĆsmo in "Diccionario panhispĆ”nico de dudas" may be worth reviewing for what the RAE's position is on this topic.
Based on this article, I think that in those regions which where "le" is accepted as a direct object for a single human male, "les" is also likely to be accepted as a direct object for a group of people that is not known to be all-female.
The article also discusses several situations where we native speakers of English might perceive a direct object but native speakers of Spanish might perceive an indirect object.