It's time to require SMB signing by default
for historical reasons (compatibility with old clients)
our default setting for smb signing is "enabled".
It's time to change the default to "required".
An admin with ancient clients can always change it back to "enabled".
Note that SMB signing can have a significant performance impact. Administrators may want to change the "SMB signing" setting to "enabled" (as it was in earlier releases) if performance is greater concern than defense against "man in the middle" attacks.