From decentralised perspective the verification data is stored in the verifiers PDS rather than having the verified-certificate in the subjects PDS which means this particular check is always for the official BlueSky server only and won’t be federated anywhere else. Other potential servers are free to implement their own (potentially different!) local verification scheme with it, but it’s never going to be network wide and it never federates anywhere except the server where it’s implemented.

This is why I commented earlier about their decision to move to ”traditional” social networking space and away from decentralised networking