Yes, indeed. In this case installer creates different subvolume layout and does not add /.snapshots to /etc/fstab.
I tested rollback in such configuration, and it appears to work after manual mount. I.e. after booting into read-only snapshot do
“mount -o subvol=@/.snapshots /dev/XXX /.snapshots” (where /dev/XXX is your root device) and issue “snapper rollback”. After reboot you will need to add /.snapshots to /etc/fstab. From now on all future snapshots will capture updated /etc/fstab and rollback should work as documented. All snapshots created before this point in time still require manual workaround (because they do not mount /.snapshots automatically).