Help finding a discussion @Riot or anyone else

Hello,

I am in the midst of having a brain baby on some support ideas I've been having, but I cannot seem to find a particular discussion that Riot gave at some point.

The discussion went along the lines of "ADC's and Mages back to buy items; Supports don't need to do this, so we made Sightstone refill on back rather than recharge so that Supports have a chance to buy items."

I would LOVE it someone could help me find this discussion so that I can better assess my ideas.

Thanks