It's fairly common for companies to instruct interviewers not to tell candidates why they failed if they reach out for fear of being sued over the response. It

It's fairly common for companies to instruct interviewers not to tell candidates why they failed if they reach out for fear of being sued over the response. It really sucks for candidates, but given that it essentially costs companies nothing to have this policy, I'm not surprised they do; no company is going to make a choice that has even a small risk of a huge negative downside if there are no direct obvious upsides to counter it.