I agree that the passwords themselves don't expire. The meaning I'm trying to convey is that if you shared the URL in an email, for example, the password assoc

I agree that the passwords themselves don't expire. The meaning I'm trying to convey is that if you shared the URL in an email, for example, the password associated with that URL would no longer be accessible. It's quite likely the password itself has been written down. Perhaps a better marketing message is as you suggest, 'Password URLs that expire'