Note that this is for the web UI of their "B2" file-sharing service, and not general backups. Did their web UI for backups have the same issue? What meta-data

Note that this is for the web UI of their "B2" file-sharing service, and not general backups. Did their web UI for backups have the same issue? What meta-data and file name info is sent to Backblaze when using their end-to-end encryption option for backups?