It was a rhetorical question :P

The section of the announcement is emphatically about 3rd party security keys support, so the worry about lack of support of YubiKey over some push for some imaginary Apple Dedicated Key didn't make much sense to me.

Also, security key (at least to me) implies a small, keychain sized device. I wouldn't think of calling my Mac Studio a security key. There is no device marketed as such, even though yes, the SEP can and has fulfilled these purposes.

You don’t have to guess the announcement actually tells you 3rd party keys can be used and NFC keys can be tapped on the iPhone.