How so? Unlike the OT Lucas actually directed the prequels and everything about them, with less studio interference than ever. He also pioneered digital filmmaking.
Lucas' influence on contemporary film is practically second to none but the filmmaker he was back when he was hanging with Coppola and Scorsese making films like American Graffiti and THX is markedly different than the filmmaker who directed the prequels.
Being a true auteur is more than just exercising absolute control over production and filming; it's about creating something of genuine artistic vision regardless of public response or commercial sensibilities and while I think Lucas has retained some of his previous auteur-ism, I don't think anything in the prequels was as bold or challenging as what Rian did with TLJ and I think that's because Lucas isn't nearly as passionate about the SW universe and instead is more pragmatic in terms of what he sees it as. (Revenue)