Past updates of my Thunderbird email software didn't disturb my past emails, so I could continue to access them. The update to Thunderbird 102.131 appeared to wipe out my past emails. They could only be downloaded from my email server. As a result, it appeared I lost most of my email history. I didn't see an option (or a suggestion) to back up my email history before making the update. If the history would have been lost, the update procedure should have included a step to backup the email history before proceeding with the update.
Later the same morning, my email history "reappeared", so the problem has been resolved. (Relief!)