Vision and Invisible Champions

It seems to me that the majority of the vision/sight/true sight changes that Riot makes are an attempt to shape the "vision battle" into a healthier state for every player in the game. This is just fine, but I feel like every time sweeping (ha) changes are made, they have tangential but extreme impacts on champions with some kind of invisibility mechanic. For example, in season 3, if I was playing against a shaco jungle, I could plop a pink ward in the middle of my lane and not have to worry so much. I couldn't do that in season 4, but, in a different example, if Rengar was ulting towards my backline, I could power up my upgraded sweeper trinket and see him coming.

So I guess my questions are: -Is there some kind of plan for invisible champions? -Why is champion invisibility and ward invisibility even the same? Wouldn't it be simpler to just separate those levers and pull them individually?