ZFS is baked in by default and the os is rock solid stable. It follows the same philosophy as Debian really, only the most tried and tested code makes it into the os.
The alternative is that his words are bald faced lies and he believes he's all but winking at the "adults in the room" that "of course he'll never actually do this".
They're both equally horrible, and sadly equally possible.
ZFS is baked in by default and the os is rock solid stable. It follows the same philosophy as Debian really, only the most tried and tested code makes it into the os.