The question is does FreeBSD make binary package updates, or are security
updates source-patch only.
From what I've observed, the base OS updates are source-patch only, at least
until the next full FreeBSD release. Anything that's in the ports tree
should be available as either a source update or as a binary package, though
the binaries lag being the source ports slightly.
You have to keep in mind that unlike most Linux distros, the BSDs (at least
FreeBSD, the only one I've used) do not treat everything as part of the OS.
Some apps (Sendmail, BIND, OpenSSH, etc.) are distributed as part of the OS;
others (Perl, SpamAssassin, Apache, etc.) are treated as additions. I think
of it like power-ups in video games. The Linux approach is like Mario eating
a mushroom and growing in size - it changes your basic structure. The BSD
approach is like picking up a new gun - still separate, but usable.
