I love how you keep proving my point for me and don't even realize it. Several people have provided you a variety of legitimate reasons to allow numbers to be announced, but your answer boils down to "we haven't done it in the past and don't need to do it in the future." Of course now you've added that it's an invasion of privacy and a possible threat to the person identified.
Apparently Magician, you may have inadvertently overlooked the first, and perhaps most important part, part of my previous response. I'll highlight it here, for your contemplation;
"Apparently, we see the possible negative effects of this issue differently. Sometimes that's the best that can be accomplished. Fortunately, we each have the option, and the ability to respond as we consider correct". In addition to your assessment that, "your answer boils down to "we haven't done it in the past and don't need to do it in the future." my position includes a long standing realization and concern, as previously stated, that NFHS Rules are designed for INTERSCHOLASTIC Sports, which usually involve a significant majority of student athletes, as well as supporters and fans, who have yet to reach "maturity".
NFHS Rules generally apply to participants between the ages of 8/10 yrs to upper teens, as opposed to young adult (NCAA) and professional adult (NFL) participants who function at more mature and experience levels. Different Football Rules codes have evolved somewhat differently to accommodate these inherent differences, unique to their participants.
Please excuse my hesitation to accept any of the "variety of reasons" (thus far suggested) to allow numbers, and the personal identify of players, to be publicly announced and called to attention, in the NFHS environment, as anywhere near "Legitimate", or more importantly, "Necessary" or beneficial to the game, or it's participants.
Perhaps rather than requiring justifications to prevent this change, focus should be concentrated on providing necessity, or convincing reason, for adopting it, along with existing potential, and relevant, consequences.