IIRC these keys are often produced in batches to help protect anonymity so revoking them may have undesirable impact on the bystanders who happen to have a key

IIRC these keys are often produced in batches to help protect anonymity so revoking them may have undesirable impact on the bystanders who happen to have a key in the same batch. So if we could reliably extract keys it may be enough to break this. (or force TPM makers to have per-device keys instead of per-batch keys)