Which is why it's nice that none of the biometric auths can be used without also having a PIN for backup auth. And also why it's nice that you can disable biometrics entirely.
The comment was aimed at the Snowden example. If Snowden thought his pin was compromised he could always change his pin, but once his face is compromised what does he doe?
not use faceID?
This entire article was explicitly written to address this line of thinking, and IMO does so very well.