If i got my phone stolen, this is exactly want i would want.... I can't use it, but neither can the person who stole it.. And isn't that the idea ?
What does that have to do with if your phone gets stolen? Without the pin or a fingerprint, there is no way to unlock it. Replacing the touchID sensor will not help hack it. The sensor needs to send some data to the secure enclave, if you have a stolen phone you don't have the data to send.
This is to help if a malicious touchID sensor is installed that also logs your fingerprints. But if that were the case, the proper fix is to disable the touchID sensor, not to brick the phone.
For what it's worth, if my phone got stolen, I wouldn't mind it being remote-bricked. But that has nothing to do with the fingerprint sensor or this security issue.