Why does duskblade have a free Oracles on it?

The item is already overloaded enough. It doesnt need a free Oracles tacked onto it thats actually even better because it automatically activates when theres a ward instead of you guessing.

Only thing about it that isnt better than Oracles is that the cooldown is higher.

I feel Irrelevant as a support trying to control vision with EOTW and EOTO (sightstones) and Oracles yet the enemy Jhin who shouldnt even be able to build duskblade can do this for free with yellow trinket+duskblade.