Doesn't matter, you don't want to risk potentially burning bridges. The expectation of confidentiality is reasonable in interviewing, and I won't violate it.
I'm currently working at a company that I interviewed unsuccessfully at seven years prior to getting the job. If I'd written up some big tell-all about the experience and waited a year and a day to publish it, it might've come up in a Google search from this round and revealed me as untrustworthy.