I'm unclear how this will solve the underlying root cause of the coding interviews -- if you are matched up with a stranger, how are they supposed to know whether you are all talk or whether you can deliver?

Referrals from people you have worked with before make sense - you know their work. But having a conversation with another engineer and expecting that to become a referral sounds odd - such interactions don't give the same level of knowledge of one's work as having actually been on the same team.