Ansel needed to limit the exposure of the moon because if it fell much higher he would have lost detail in the negative. And you forgot the rest of the story about how the moon was properly exposed but the foreground was very thin. His materials were more limited so he had to make decisions like this. With current films there is no reason to worry about the moon and make the other 98% of the image harder to print. If the moon is on Zone VII, VIII, IX full detail will be retained. You just burn it in on the print.