This was my understanding as well. Keybase goes further in that they do not have access to the file metadata either (only size, not even count - though by their own admission they could probably reverse engineer count if they tried hard).
You don't even register a single root PK with them anymore - you end up with a network of device-specifc and paper keys in their current security model. IMO, their current client is the most nontechnical-user friendly security app I've ever had the privilege to use.
