It depends whether they want someone near their own age or someone who has been and still is performing during their life time. I don’t think we have any really striking (could well be wrong, am open to correction!) younger ones who immediately hit the spot for their generation (and subsequent ones) as did Marilyn, Elvis, Audrey etc. But we do have Judi Dench...who has enchanted us with her performances for decades and continues to do so. She is older than many of GNs but 40 year olds would have grown up with her and she would surely be an icon to them. If it can be for the portrayal of a single, iconic, character then Carrie Fisher would definitely be one.