From my limited understanding of this site, and the predecessor sub, it’s a specific reference to a historical figure (presumably a “based” one), in exactly the same way AoV is. In order to completely preserve the anonymity of the mods, at least name-wise…

Much like your screen name.

I did look up who the actual Dom of Massillia was, at one point. Some king who lived thousands of years ago in the “near East”, I believe…