The command testparm -v only lists vfs_fruit options that have been manually configured in the smb.conf (whether or not they are set to what the manpage indicates are default values). It is my recollection that in Samba 4.13.x this command would list all options, even those not manually configured. And, if not manually configured, it would display them with the default values as indicated in the vfs_fruit manpage. See: https://www.samba.org/samba/docs/current/man-html/testparm.1.html in particular, in the "Options" section: -v|--verbose If this option is specified, testparm will also output all options that were not used in smb.conf(5) and are thus set to their defaults.
Changed the Component type of the bug, because "Other" didn't seem the right fit.