I'm sceptical; I've heard this before but never managed to track down a source; I also don't know if you need some specific wording for this or if it's so vague as to be useful. Case in point: when I've failed my google interviews in London, I asked for the feedback, and got a reply saying something like "Sorry, we don't do detailed feedback. We weren't happy with your performance on the interviews". Which, duh, I got that from the being rejected part :P