I don't think that this is true. After a buck sheds his antlers he is sterile until until after he sheds the velvet from his new rack. You can see this when a late born fawn comes into heat late into the season. Like in march. Instead of attracting all bucks, shed or not, only younger bucks that still have their antlers are the ones doing the breeding of these late bloomers. In a captive situation this may be different, they may still have the urge to breed, but they'll be shooting blanks. In the wild, older bucks that have shed are not interested in breeding and they don't.