I have been playing since MoP launch and its about 3 weeks ago i got my cloak. I had lei shen dropping one titan runestone already. So there was no 0 drop week. if u experience 0 drop in titan runestone, that means u got ur secrets so fast that u were able to start befor the lei shen change. Some of my lucky friends go the cloak even 4 weeks before me.
And regarding this not being a weapon, i m very happy with it being cloak, cloak or weapon is irrelevant to me. its just a piece of gear, all that matters to me is whether its giving me legendary stats, and yes its serving that purpose well.