That's not the only possible attack here: FIDO direct attestation requires a key to be shared among either none or at least 100 000 devices (for privacy reasons):
> If the authenticator puts the exact identical attestation key into a group of Authenticators (e.g., group of devices, phones, security keys...) so that the attestation key doesn't become a Correlation Handle, then each group of Authenticators MUST be at least 100,000 in number. If less than 100,000 Authenticators are made, then they MUST all have the same attestation key.
Yubico, to my knowledge, has chosen the latter route; this means that compromising a single Yubikey's attestation key compromises at least 100k others immediately
> If the authenticator puts the exact identical attestation key into a group of Authenticators (e.g., group of devices, phones, security keys...) so that the attestation key doesn't become a Correlation Handle, then each group of Authenticators MUST be at least 100,000 in number. If less than 100,000 Authenticators are made, then they MUST all have the same attestation key.
Yubico, to my knowledge, has chosen the latter route; this means that compromising a single Yubikey's attestation key compromises at least 100k others immediately