well , you can get it in the pit maybe already which is still is anticlimatic xD
but i agree that this specific item could be linked to baal , like some kind of specific drop to him.
for example , each boss of hell having a specific drop to it.
Andariel visage for andariel , tyrael might for baal etc…
though for tyrael might , considering how low the density of monsters is in the den of evil , i doubt people would actively farm there.
atleast the pit got way higher density + the magical chests.