Does the SpamAssassin port really need to delete sa-update keys?

[Mike Brown]

Since 2007, the mail/p5-Mail-SpamAssassin/pkg-plist contains this:
@unexec rm -rf %D/etc/mail/spamassassin/sa-update-keys

Why does it remove the sa-update-keys directory? There's no reason
given in the commit message.

As a result of deleting the keyring, every time some upgrades SpamAssassin, if 
they're using GPG with sa-update, they have to remember to re-fetch the 
channel keys from wherever and "sa-update --import" them.

Why not just leave the keyring in place? Is there a security risk?