Sion's W interaction (possibly a bug)

So I recently filed a support ticket about the interaction between the passive of soul furnace and zz'rot portal and Banner of Command and they recommended that I make a post about it on the boards so i decided to.

I don't actually know if this is a bug or is intended but judging by the description (of soul furnace) it should probably grant sion HP when zz'rot/BoC kills a minion. But the last thing sion needs right now is a buff so I don't really know if this would be fair.

https://support.riotgames.com/hc/en-us/requests/21395030 (the original support ticket)