Advertisements are already photo-shopped and completely fake. Knowing that the models are AI generated doesn't change much about that. It could actually have a beneficial effect. If young people (especially girls) know that the images they see on-screen are 100% computer generated, maybe it will reduce their effectiveness at convincing them that the ad is an object worthy of emulation.
I'm sure the advertisers will scientifically test for this effect and use whatever strategy keeps them buying though...