Comment 3 for bug 175161

The file system name and others informations are always available in LUKS partition. Only the content of file system itself is encrypted, so Gparted can gather these informations and show the real file system name to the final user, it could also see that the partition is encrypted and the algorithm used.

Since I can't reproduce that bug here, we would need somebody who's able to reproduce that bug with gparted in order to confirm this bug report.