Once the certificate becomes obsolete, it becomes useless and therefore needs to be reacquired. Same process with American SSNs, if they were depreciated very 6 months getting yours published wouldn’t be an issue.
When my vaccination pass would "leak" then my name & birthdate would be leaked and they would know someone of that name and birthdate got vaccinated but other than that, they can't impersonate me as if they presented the pass they would be asked to show the corresponding ID as well.