Infernal Harpoon is a thing, but does not work on Alora. If anything they should all be made functional first. But directly regarding your suggestion, I do Not Support the idea. If you die to an NPC, the item will be dropped on the ground and will remain for a specified amount of time for you to go pick it back up.
If this were to be implemented, in the situation (Imagine this); you are in the Resource Area, level 52 wilderness, mining, with your Infernal PIckaxe. A PK'er comes and kills you. If you're not skulled you should already keep the item. If however you are skulled and are killed by another player, without protect item on, the Infernal Pickaxe should be fairly be dropped for the person who killed you to loot. BUT because your suggestion was implemented, it unfairly goes to the Untradables Shop and you will have risked nothing. 
This suggestion would serve no purpose in PVM situations, and act as an unfair advantage in PVP situations.