I personally tried to stay apprised of passkey's development. After asking several developers and poking around the best I could, I was told several times that it was being primarily developed behind closed doors for corporate interests, invite-only, and wasn't ready for release. The only information available was the WebAuthn forums.
Even now the documentation is still poor, and there's essentially no rationale to understand design and architectural decisions. We're just given a spec and expected to adhere to it.
Saying that "WebAuthn was much more public, but passkey was not." shows that you don't really have a clear and accurate mental model of what passkeys are. Maybe TFA might help?