Test assertions requirement

(Bcc'd public-css-testsuite; can we please keep responses on a single
mailing list, in this case www-style as it's about a WG resolution?)

In the SF F2F, 2016-05-09 we resolved:

RESOLVED: testharness.js tests don't need a meta assert (but reftests
still do)

>From memory, this was based on a mistaken understanding that assertions
were currently required everywhere.

This seems to contradict all documentation going back almost a decade!
In 2007 fantasai updated the wiki in
<https://wiki.csswg.org/test/format?do=diff&rev2%5B0%5D=1184350761&rev2%5B1%5D=1186099916&difftype=sidebyside>
to state that assertions are optional (generically!).

I've been unable to find any discussion leading to this change, though
obviously discussion was happening around then (see
<https://lists.w3.org/Archives/Public/public-css-testsuite/2007Jun/0024.html>
for example).

Do we want to revisit the resolution in light of being mistaken as to
previous policy? Or do we just want to consider the documentation wrong?

/Geoffrey