Agreed - the first distribution required registration prior to the announcement. I don't see why that didn't apply completely, why use it to drive Keybase sign-ups? They were essentially all 'fake users'.
Even the first distribution temporarily put a market value on old GitHub accounts, since their anti-grab measure was that you needed a pre-existing Keybase account or a new one linked to a pre-existing GitHub account. There were several people on /r/github confused why they were getting monetary offers to buy their accounts. That already didn't sound like the intended outcome.
