Yea I see the same but I believe, according to their blog post, they are rolling out support on workspaces at a later date.

https://blog.google/technology/safety-security/the-beginning...

This is odd - as soon as this became available, I created a passkey on my Workspace account, but now it says "Passkeys aren’t allowed on this account". And it still prompts me to "simplify my sign-in experience" when I sign in on this account.