I tried to run etcupdate -- it's been a while, and I felt I should.
I got the following message:

# etcupdate
*** Creating /tmp/temproot
*** Populating /tmp/temproot from /usr/src/etc
install: etcsubmit.cf: stat: No such file or directory

I'm not sure where it's supposed to be.  It was built:

# find /usr/BUILD -name etcsubmit.cf -print
/usr/BUILD/obj/gnu/usr.sbin/sendmail/cf/cf/etcsubmit.cf

but since I run postfix I've never wondered if I should have such a file.