They could at least allow hiring teams to send out a feedback email that highlights what the candidate did WELL, at a high level. This way the candidate gets some meaningful signal, while the company avoids the legal gray area of admitting why they rejected them. Just add a disclaimer like “unfortunately company policy prohibits us from explicitly mentioning why we chose another candidate.”

But you’d need to actually care to take something like that into consideration so… ¯\_(ツ)_/¯

Have you ever talked to a lawyer? The only thing that they keep repeating is "shut your mouth".