Heh, I'm afraid to say anything here, some person felt that I was being insulting on FreeBSD forums, when I'm really far too old to get into forum fights.
https://forums.freebsd.org/threads/55560/
Anyway, it seems interesting, but as has been mentioned, there have been other efforts by Debian and Arch,and probably Gentoo, which probably attracts more with an interest in FreeBSD than others, that just haven't taken off. I also think Ubuntu may ask them to use a different name.
I was thinking of trying in VirtualBox. As Mike Lucas said, lightheartedly on twitter, it's one way to legally get ZFS on Linux.