I think that something can be said for the idea that AV is just SE's little beta testing toy. It does generate a lot of interest amongst the player base, some of whom pay their monthly fee with faith that they'll discover the "secret" to killing it. I mean, SE doesn't really have to do much other than dangle Ninurta's sash about and continually patch the crap out of their creature - the unattainable always does have a more elusive appeal.
As for the whole 18 hour fight deal, they could just turn around and say "you're not doing it right, you don't have to fight AV lols"
But something confuses me (forgive me if I am otherwise misinformed or havent read all the information here). From what I gathered, the development team took quite a while to take down AV in their vid. Now if it has been patched to depsawn after two hours, is it still even feasible to implement their strat (if it is eventually uncovered)?