I beleive the URL http://www.gnu.org/links/links.html#FreeGNULinuxDistributions%20. has been referenced in other messages declaiming Richard's recommendation of this or that Distro.
This link was also near the top of the bsdtalk page about the RMS interview. The explanation - near the top, of why many Distro's including BSD's can not be listed, is terse. Whether it is the complete criteria would be a question for Richard. Regardless, it is clear that OpenBSD comes close but fails to meet these criteria. If OpenBSD-misc insists that Richard Stallman become intimately familiar with the policies of OpenBSD and the technical details of the OpenBSD implementation of ports then it is reasonable that we should actually read the information that is readily available concerning the criteria for his recommendation.